drupal call ajax function
> $delete_commant = l(t('X'), $url, array('attributes' =>
> array('onclick' => 'return call_ajax(123)')));

when i put alert in call_ajax function definition, it is alerted, so i proceed to write the ajax post method, but when i click the link page getting refresh,

How to implement ajax in drupal

    function call_ajax(str){alert(str);
    	var url = "post.php";
    	var params = "lorem=ipsum&name=binny";
    	http.open("POST", url, true);
    
    	//Send the proper header information along with the request
    	http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    	http.setRequestHeader("Content-length", params.length);
    	http.setRequestHeader("Connection", "close");
    
    	http.onreadystatechange = function() {//Call a function when the state changes.
    		if(http.readyState == 4 && http.status == 200) {
    			alert(http.responseText);
    		}
    	}
    	http.send(params);	
         }
drupal call ajax function
===

> $delete_commant = l(t('X'), $url, array('attributes' =>
> array('onclick' => 'return call_ajax(123)')));

when i put alert in call_ajax function definition, it is alerted, so i proceed to write the ajax post method, but when i click the link page getting refresh,

How to implement ajax in drupal

    function call_ajax(str){alert(str);
    	var url = "post.php";
    	var params = "lorem=ipsum&name=binny";
    	http.open("POST", url, true);
    
    	//Send the proper header information along with the request
    	http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    	http.setRequestHeader("Content-length", params.length);
    	http.setRequestHeader("Connection", "close");
    
    	http.onreadystatechange = function() {//Call a function when the state changes.
    		if(http.readyState == 4 && http.status == 200) {
    			alert(http.responseText);
    		}
    	}
    	http.send(params);	
         }