Ajax post help!

[six]

Hello,
I'm having trouble with posting data from a dynamic collection.

my code:
[code=php:0]

function TestPost(strForm){

xmlHttp=GetXmlHttpObject()
var str = FormCollection(strForm);
//var str = "firstname=ken&lastname=scott";
var url = "post.asp";
xmlHttp.open("POST",url,true);
xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
xmlHttp.send(str);

}

[/code]

ok, if i use:
var str = "firstname=ken&lastname=scott";
is posts the data no problem every time, the thing is that i have alot of form posts on my site and would like to use a dynamic collection method.

[code=php:0]
function FormCollection(theform){

    querystring='';

    for (var i = 0; i<theform.elements.length; i++) {
if(i==0){
    querystring += theform.elements[i].name + "=" + theform.elements[i].value;
} else {
    querystring += "&" + theform.elements[i].name + "=" + theform.elements[i].value;
}
}

document.getElementById("result").innerHTML = querystring; // for testing only
}
[/code]

which will build a string like this: "firstname=ken&lastname=scott" from my current form, the problem is, that it only actually added the string to the date when i staticly enter the data, when i use :
var str = FormCollection(strForm);
it just posts an empty record. yet it return the correct string with i write it out to a <div>. i was hoping that someone here might have some idea what i can do to make this work..

hoping this is the correct forum for this issue.

thanks in advance for your time!
-Ken

[gluck]

Where are you returning the querystring to the function?