a problem with a simple function

[php_member]

I have no idea why the function is not working if I put on the 4th line Example instead of 'test'. So if I put if(document.getElementById('test').value=='') is working, if I put if(document.getElementById(Example).value=='') is not working. Why test is not passed via Example? It must be some dummy mistake I can not find it! Please help me.

function validate(Example) {
 var isGood = true;
 //validate test
 if(document.getElementById('test').value=='')
 {
 isGood = false;
 }
 //return true or false
 if (isGood== false)
 {
 alert (isGood);
 }
 return isGood;
}
$(function() {
 $('#addquestion').click(function() {
  $('<input id="test" type="text" name="text1" /><br />').appendTo('#to_moreoptions');
  if(document.getElementById('formid').value=='vrednost')
   {
   validate('test');
   }
 });
});

[php_member]

I will make more simple question. The problem is that 'test' is not passed. The following function alert undefined, but it should alert test.

function validate(Example) {
var isGood = true;
alert(Example);
}

$(function() {
//if I put validate('test') here, it will alert test
if(document.getElementById('formid').value=='vrednost')
{
validate('test');
}
});