Create Forms Dynamically - When The User Clicks A Button Creates A New Row Displaying A Form

I currently have a page which, when the user clicks a button creates a new row displaying a form. I also have other forms on this page how to close a form using javascript? My code to create the table row and form are below...

myform = document.createElement("form");
myform.method = "post";
myform.action = "editdetails.php";
myform.id = "editemail";
myform.name = "editemail";
var a=document.getElementById('editdetailstable').insertRow(2);
var b=document.getElementById('editdetailstable').insertRow(3);
[Code]....