...

View Full Version : Form Field Comparison



npala2001
08-02-2006, 08:37 PM
Hi guys I am new to javascript!

I have three fields that I want validated on a form. Item3 cannot be smaller than Item2 and Item2 cannot be smaller than Item1.

Below is what I had in mind:

Function validateForm()
{
If (Item3 < Item2)
alert="You must enter a bigger size for Item 3"
else
If (Item2 < Item1)
alert="You must enter a bigger size for Item 2
}
</script>

<form method="POST" action="Post.jsp" onsubmit="validateForm(this)">

Kor
08-02-2006, 09:26 PM
1. elements(objects) should be properly refered. A form's element is to be found, usually (but there are some other methods as well) as an element of the form

document.forms['formname'].elements['elementname']

2. fields' input content is controlled by the value attribute. this attribute returns always a string, not a number, so that before any Math operation or compare, the return result must be transformed in a number. One of the methods is Number().

3. Usualy, the validate follows this general pattern:

...
function validate(){
if(... condition is not fulfiled...){
alert('Hey, the condition is not fulfiled!')
return false;
}
}
.....
<form onsubmit="return validate()">
...

Now try to play with this and let us know what you have done.

npala2001
08-02-2006, 10:01 PM
Hmm very interesting. Why was this posted twice?

npala2001
08-02-2006, 11:00 PM
Do you have any links to online resources regarding this subject?

Kor
08-02-2006, 11:05 PM
the usual javascript online tutorials... Nothing special.



EZ Archive Ads Plugin for vBulletin Copyright 2006 Computer Help Forum