execute a javascript on load

Question

I want to execute this java script on load, but it doesn't seem to display the result after the browser loads.

<script>
 function displayNumber()
{
var card = document.getElementById('credit').value;
var str = "";
for(var i=1; i <= card.length-4; i++) {
 str += "*";
}
 ecard = str + card.substr(card.length-4);
 document.getElementById('output').innerHTML = ecard;
}
</script>
 <form id="myform">
 <input type="text" id="credit" onLoad="displayNumber()" value="123456789012">
</form> 
<label id="output"> </label>

The output should be

********9012

Answer 1

You cannot use onload with an input. Instead, put window.onload = displayNumber; in your JavaScript. The other option is to add a body tag and use onload="displayNumber()"