execute javascript when pag opens code example

Example 1: call a function when page is loaded

<script src="js/jquery-1.11.0.min.js" type="text/javascript"></script>
<script type="text/javascript">

    $(document).ready(function () {
        yourFunction();
    });
    function yourFunction(){
      //some code
    }
</script>

Example 2: run on load js

function codeAddress() {
            alert('ok');
        }
window.onload = codeAddress;