Pass A Value Using A Parameter In Html (asp) To A Function?

I am trying to pass a value using a parameter in html (asp) to a javascript function. When I try to pass a value inside of a variable <INPUT type="submit" value="Next Youth" name=button1 onclick="OnButton1(tst);"> it simply doesn't work (no error msg - just nothing) while if I put a value in the call <INPUT type="submit" value="Next Youth" name=button1 onclick="OnButton1('5393');"> it works fine. The javascript looks like this:

function OnButton1(tst)
{
var pth = "youth_edit3.asp?cIndex=" + tst;
document.YouthEdit.action = pth;
document.YouthEdit.submit(); // Submit the page
}

I've set tst = "5393" but it won't work when I try to pass it. Only a literal value of '5393' works.