Webmaster Forum / HTML, CSS, Scripts / JavaScript / October 2007

I have an application that puts a table of values on a page along with
a form whereby the user may add a value.  I need to make sure that the
value does not already exist in the table so I want to run a onBlur
function to check the value when they are ready to submit it.  The
cells in question are dynamically generated so I do not know before
the page loads how many cells there will be.  All cells have an ID
value of TDx, e.g. TD1 or TD14

I tried this code:
<form>
<table><tr><td id="td1">1/2/2007</td><td id="td2">3/14/2007</td></tr></
table>
<input type=text name="myvaluetotest" onBlur="checkvalue(this)">
</form>
<script language=javascript>
function checkvalue(myvar) {
 var ary,i;

 ary = document.getElementsByTagName("TD")
 for(i in ary)
 {
  alert(i + ' ' + document.getElementById('td1').innerText);
 }
}
</script>

When I run this onBlur it will run through the loop and pop up an
alert box with TD1 1/2/2007 and then one with TD2 3/14/2007.  As a
result I know that the ary = assignment is working.

However, if I try to substitute i for the 'td1' in the getElementById
property it tells me Object Required.  What is the right way to do
this?