using vars to address form elements

[lazytrucker]

Hello all, I have been trying to do this for some time now and with no success.

I have an onchange function which has to populate some form fields depending on what var is passed.

The function goes like this.

function func(val)
{
var call
call="document.fexp.a"+val; //val = 1
alert(call.value); //this returns undefined
alert(document.fexp.a1.value); //this returns the correct value
}

Is there any way to address form elements using the passed variable??
Any suggestions much appreciated

Cheers Lazy Trucker

 

[CoffeeQuick]

Change the line

call="document.fexp.a"+val; //val = 1

to

call=document.getElementById("fexp.a"+val); //val = 1

Hope this helps.

John

 

[lazytrucker]

Im afraid this doesn't work the value im trying to put into the alert() comes from a hidden text field, document.fexp.a1.value

if I give the element the same id (a1) it doesnt work.

Any other suggestions??

 

[CoffeeQuick]

Can you post the code for the form?

 

[cLFlaVA]

Try this:

alert(eval(call + ".value"));

*cLFlaVA
----------------------------
Breaking the habit...

 

[cLFlaVA]

You are trying to reference the "value" property of a string. What you want is the "value" property of a field.

The string contains this:
"document.fexp.a1"

the eval function will, well, evaluate the string. So, in my previous post, you're going to evaluate "document.fexp.a1.value" and then alert it.

Hope this helps.

*cLFlaVA
----------------------------
Breaking the habit...

 

[lazytrucker]

Thanks for the replys I thought you were on the right track with the id's so I messed about a bit and got there in the end:

Function:

function func(val)
{
var call
call=document.getElementById("a"+val);
document.fexp.depapt.value=call.value;
}

Where the hidden field looks like:

<input type="hidden" id="<%="a"&i%>" value="<%=trim(rst("aspsql"))%>">

Hope this may help others.