页面加载jquery

$(document).ready(function(){
//do something here
});

$(document).ready(function(){

  $('#yourelement').bind('click', function() {
     /* set handler onclick */

  })
  /* trigger ('run once') on domready */
  .trigger('click'); 


});

click()

$(document).load(function(){

   $('#someelement').click(function(){
      alert("some element clicked");
   });

   $('#someelement').click();
   // or $('#someelement').trigger('click');
});

http://jsfiddle.net/ZXyJH/

here

<script type="text/javascript" 
        src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
  // You may specify partial version numbers, such as "1" or "1.3",
  //  with the same result. Doing so will automatically load the 
  //  latest version matching that partial revision pattern 
  //  (e.g. 1.3 would load 1.3.2 today and 1 would load 1.4.2).
  google.load("jquery", "1.4.2");

  google.setOnLoadCallback(function() {
    // Place init code here instead of $(document).ready()
  });
</script>