1. if you wrap all your code in code tags by pressing the # button then it makes the code easier to read.
2. If you separate the JavaScript into a separate file from the HTML then it makes both easier to read and also makes validating each of them easier.
3. You don't appear to have an y combo boxes in your form. Combo boxes were only added in HTML 5 and generally would be coded as follows:
Code:
<input type="text" list="state">
<datalist id="state">
<option value="act">
<option value="nsw">
<option value="nt">
<option value="qld">
<option value="sa">
<option value="tas">
<option value="vic">
<option value="wa">
</datalist>
With a combo box the person filling out the field can either select a value from the list or enter their own value if they prefer (a combo box is a combination of a text input field and a select list).
4. Your code does contain a select list - is that what you are misidentifying as a combo box or are you attempting to convert it into a combo box using JavaScript (in which case it would be far easier to use an input field and a list as the HTML to convert).
With a form that contains a select list where the values are addresses of different pages you can attach JavaScript to the select using the
change event listener that can then redirect to the appropriate page when the selected value in the select list is changed but you can't perform any event processing on the individual options as JavaScript can only interact with complete elements in the web page and the element in this situation would be the entire select.