1. Use onload in body:
<body onload="myfunction()">
2. Use window.onload in the script:
<script type="text/javascript">function myfun(){alert("this window.onload");}/*Call myfun() with window.onload*/window.onload=myfun;//Do not brackets</script>The following example changes the background color of id_1 after the page has been loaded.
<script language="javascript" >function myfun() {document.getElementById("id_1").style.background= "#000"; // Change the background color}// Use js to implement automatic execution of a method after loading a page/*Call myfun() with window.onload*/window.onload=myfun;//Do not brackets</script>