[Beginner1]

Thank you Philip M,
is it possible to do it in same manner as code that I posted?

VAT and Margin are not constants.

Please find bellow complete script:

<script type="text/javascript">
//<!--
function toggleDisable( elementOnChecked, elementDisable, disableOnChecked ) {
	try {
		if( !disableOnChecked ) {
			if(elementOnChecked.checked==true) {
				elementDisable.disabled=false;
			}
			else {
				elementDisable.disabled=true;
			}
		}
		else {
			if(elementOnChecked.checked==true) {
				elementDisable.disabled=true;
			}
			else {
				elementDisable.disabled=false;
			}
		}
	}
	catch( e ) {}
}
// Modification.
// All rights reserved.
var tax_rates = new Array();
var profit_rates = new Array();
<?php
foreach( $profit_rates as $profit_rate_id => $profit_rate ) {
	echo "profit_rates[\"$profit_rate_id\"] = $profit_rate;\n";
}
?>
<?php
foreach( $tax_rates as $tax_rate_id => $tax_rate ) {
	echo "tax_rates[\"$tax_rate_id\"] = $tax_rate;\n";
}
?>
function doRound(x, places) {
	return Math.round(x * Math.pow(10, places)) / Math.pow(10, places);
}

function getTaxRate() {
	var selected_value = document.adminForm.product_tax_id.selectedIndex;
	var parameterVal = document.adminForm.product_tax_id[selected_value].value;

	if ( (parameterVal > 0) && (tax_rates[parameterVal] > 0) ) {
		return tax_rates[parameterVal];
	} else {
		return 0;
	}
}
<!--vmelektronik changed for profit margn-->
function getProfitRate() {
	var selected_value = document.adminForm.product_profit_id.selectedIndex;
	var parameterVal = document.adminForm.product_profit_id[selected_value].value;

	if ( (parameterVal > 0) && (profit_rates[parameterVal] > 0) ) {
		return profit_rates[parameterVal];
	} else {
		return 0;
	}
}
<!--end of vmelektronik changed for profit margn-->
//changed by vmelektronik for profit margin.
function updateProfit() {
	if( document.adminForm.product_profitmargin_price.value != '' ) {
		var profitRate = getProfitRate();

		var r = new RegExp("\,", "i");
		document.adminForm.product_profitmargin_price.value = document.adminForm.product_profitmargin_price.value.replace( r, "." );
		document.adminForm.product_price_incl_tax.value = document.adminForm.product_price_incl_tax.value.replace( r, "." );

		var netValue = document.adminForm.product_profitmargin_price.value;

		if (profitRate > 0) {
			netValue = netValue * (profitRate + 1);
		}
		document.adminForm.product_price.value = doRound(netValue, 5);
	}
}
// end of profit margin change
function updateGross() {
	if( document.adminForm.product_price.value != '' ) {
		var taxRate = getTaxRate();

		var r = new RegExp("\,", "i");
		document.adminForm.product_price.value = document.adminForm.product_price.value.replace( r, "." );

		var grossValue = document.adminForm.product_price.value;

		if (taxRate > 0) {
			grossValue = grossValue * (taxRate + 1);
		}

		document.adminForm.product_price_incl_tax.value = doRound(grossValue, 5);
	}
}

function updateNet() {
	if( document.adminForm.product_price_incl_tax.value != '' ) {
		var taxRate = getTaxRate();

		var r = new RegExp("\,", "i");
		document.adminForm.product_price_incl_tax.value = document.adminForm.product_price_incl_tax.value.replace( r, "." );

		var netValue = document.adminForm.product_price_incl_tax.value;

		if (taxRate > 0) {
			netValue = netValue / (taxRate + 1);
		}

		document.adminForm.product_price.value = doRound(netValue, 5);
	}
}

function updateDiscountedPrice() {
	if( document.adminForm.product_price.value != '' ) {
		try {
			var selected_discount = document.adminForm.product_discount_id.selectedIndex;
			var discountCalc = document.adminForm.product_discount_id[selected_discount].id;
			<?php if( PAYMENT_DISCOUNT_BEFORE == '1' ) : ?>
			var origPrice = document.adminForm.product_price.value;
			<?php else : ?>
			var origPrice = document.adminForm.product_price_incl_tax.value;
			<?php endif; ?>

			if( discountCalc ) {
				eval( 'var discPrice = ' + origPrice + discountCalc );
				if( discPrice != origPrice ) {
					document.adminForm.discounted_price_override.value = discPrice.toFixed( 2 );
				} else {
					document.adminForm.discounted_price_override.value = '';
				}
			}
		}
		catch( e ) { }
	}
}
function toggleProductList( enable ) {
	if(enable) {		
    	document.getElementById('list_style0').disabled = false;
       document.getElementById('list_style0').checked = true;
    	document.getElementById('list_style1').disabled = false;
       document.getElementById('display_headers').disabled = false;
    	document.getElementById('product_list_child').disabled = false;
       document.getElementById('product_list_type').disabled = false;
	}
    else {
    	document.getElementById('list_style0').disabled = true;
    	document.getElementById('list_style1').disabled = true;
       document.getElementById('display_headers').disabled = true;
    	document.getElementById('product_list_child').disabled = true;
       document.getElementById('product_list_type').disabled = true;
       document.getElementById('display_headers').checked = false;
    	document.getElementById('product_list_child').checked = false;
       document.getElementById('product_list_type').checked = false;
	}
}
updateGross();
updateDiscountedPrice();
updateProfit();
<?php
if( @$_REQUEST['no_menu'] != '1') {
	?>
	toggleDisable( document.adminForm.product_full_image_action[1], document.adminForm.product_thumb_image, true );
	<?php
}
?>
var productSearchField = function(){

    var relds = new Ext.data.Store({
        proxy: new Ext.data.HttpProxy({
            url: 'index2.php?option=com_virtuemart&page=product.ajax_tools&task=getproducts&ajax_request=1&func=&no_menu=1&only_page=1&no_html=1&product_id=<?php echo $product_id ?>',
            method: 'GET' }),
        reader: new Ext.data.JsonReader({
            root: 'products',
            totalProperty: 'totalCount',
            id: 'product_id'
	        }, [
	            {name: 'product'},
	            {name: 'category'},
	            {name: 'product_id'}
	        ])
    });   
    // Custom rendering Template
    var resultTpl = new Ext.XTemplate( '<tpl for="."><div class="x-combo-list-item">{category} / {product}</div></tpl>' );
    relatedSelection = document.getElementById('relatedSelection');
    related_products = document.adminForm.related_products;
    var relProdSearch = new Ext.form.ComboBox({
    	applyTo: 'relatedProductSearch',
        store: relds,
        title: '<?php echo addslashes($VM_LANG->_('VM_PRODUCT_SELECT_ONE_OR_MORE')); ?>',
        displayField:'product',
        typeAhead: false,
        loadingText: '<?php echo addslashes($VM_LANG->_('VM_PRODUCT_SEARCHING')); ?>',
        width: 270,
        minListWidth: 270,
        pageSize:15,
        emptyText: "<?php  echo addslashes($VM_LANG->_('PHPSHOP_SEARCH_TITLE')); ?>",
        tpl: resultTpl,
        onSelect: function(record) {
        	for(var i=0;i<relatedSelection.options.length;i++) {
        		if(relatedSelection.options[i].value==record.id) {
        			return;
        		}
        	}
        	o = new Option( record.data.product, record.id );
        	relatedSelection.options[relatedSelection.options.length] = o;
        	if( related_products.value != '') {
        		related_products.value += '|' + record.id;
        	} else {
        		related_products.value += record.id;
        	}
        }
    });
	
};
var categorySearchField = function(){

    var relds = new Ext.data.Store({
        proxy: new Ext.data.HttpProxy({
            url: 'index2.php?option=com_virtuemart&page=product.ajax_tools&task=getcategories&ajax_request=1&func=&no_menu=1&only_page=1&no_html=1',
            method: 'GET'            
        }),
        reader: new Ext.data.JsonReader({
            root: 'categories',
            totalProperty: 'totalCount',
            id: 'category_id'
	        }, [
	            {name: 'category'},
	            {name: 'category_id'}
	        ])
    });
   
    // Custom rendering Template
    var resultTpl = new Ext.XTemplate(
    	'<tpl for="."><div class="x-combo-list-item">{category} (ID: {category_id})</div></tpl>'
    );
    relatedCatSelection = document.getElementById('relatedCatSelection');
    category_ids = document.adminForm.category_ids;
    var relProdSearch = new Ext.form.ComboBox({
    	applyTo: "categorySearch",
        store: relds,
        title: '<?php echo addslashes($VM_LANG->_('VM_PRODUCT_SELECT_ONE_OR_MORE')); ?>',
        displayField:'category',
        typeAhead: false,
        loadingText: '<?php echo addslashes($VM_LANG->_('VM_PRODUCT_SEARCHING')); ?>',
        width: 170,
        minListWidth: 170,
        pageSize:15,
        emptyText: "<?php  echo addslashes($VM_LANG->_('PHPSHOP_SEARCH_TITLE')); ?>",
        tpl: resultTpl,
        onSelect: function(record) {
        	for(var i=0;i<relatedCatSelection.options.length;i++) {
        		if(relatedCatSelection.options[i].value==record.id) {
        			return;
        		}
        	}
        	o = new Option( record.data.category, record.id );
        	
        	relatedCatSelection.options[relatedCatSelection.options.length] = o;
        	if( category_ids.value != '') {
        		category_ids.value += '|' + record.id;
        	} else {
        		category_ids.value += record.id;
        	}
        }
    });
	
};
if( Ext.isIE6 || Ext.isIE7 ) {
	Ext.EventManager.addListener( window, 'load', productSearchField );
	if( Ext.get("categorySearch") ) {
		Ext.EventManager.addListener( window, 'load', categorySearchField );
	}
}
else {
	Ext.onReady( productSearchField );
	if( Ext.get("categorySearch") ) {
		Ext.onReady( categorySearchField );
	}
}
function removeSelectedOptions(from, hiddenField ) {
	field = eval( "document.adminForm." + hiddenField );
	// Delete them from original
	var newOptions = [];
	for (var i=(from.options.length-1); i>=0; i--) {
		var o = from.options[i];
		if (o.selected) {
			from.options[i] = null;
		} else {
			newOptions.push(o.value);
		}
	}
	field.value = newOptions.join('|');
	
}
//-->
</script>