function f_addLoadEvent(func)
{
	var oldonload = window.onload;
	if(typeof window.onload != 'function')
	{
		window.onload = func;
	}
	else
	{
		window.onload = function()
		{
			oldonload();
			func();
		}
	}
}

function f_getEvent()
{	
	var o_myform = document.getElementsByTagName('form')[0];
	o_myform.onsubmit=f_newMessage;	
}

function f_createXMLHttpRequest() 
{
    if (window.ActiveXObject) 
    {
        var o_xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    else if (window.XMLHttpRequest) 
    {
    	var o_xmlHttp = new XMLHttpRequest();
    }
    if(o_xmlHttp)
    {
		return o_xmlHttp;
    }
    else
    {
    	return false;
    }
}

function f_newMessage()
{
	var s_message_name    =  document.getElementById('message_name').value;
	var s_message_email   =  document.getElementById('message_email').value;
	var s_message_topic   =  document.getElementById('message_topic').value;
	var s_message_content =  document.getElementById('message_content').value;
	var s_message_emptydenied =  document.getElementById('prompt_message_emptydenied').value;
	if(s_message_topic == '' || s_message_content =='')
	{
		alert(s_message_emptydenied);
		return false;
	}
	var s_message_allinone;
	//escape &,because the post method of ajax will cut off the string when it encounter char '&';
	s_message_allinone = 's_message_name='+s_message_name.replace(/&/g,'%26')+'&s_message_email='+s_message_email.replace(/&/g,'%26')+'&s_message_topic='+s_message_topic.replace(/&/g,'%26')+'&s_message_content='+s_message_content.replace(/&/g,'%26');
	s_message_allinone = s_message_allinone.replace(/\\/g,'');
	var o_ajaxXmlHttp = f_createXMLHttpRequest();
	if (o_ajaxXmlHttp)
	{
		o_ajaxXmlHttp.open('POST','./message_site_engine_new.php',true);
		o_ajaxXmlHttp.setRequestHeader('Content-Type','application/x-www-form-urlencoded;charset=UTF-8');
		o_ajaxXmlHttp.send(s_message_allinone);
		o_ajaxXmlHttp.onreadystatechange = function()
		{
			if (o_ajaxXmlHttp.readyState == 4) 
			{

 	   			 if (o_ajaxXmlHttp.status == 200) 
 	    			{
						if(o_ajaxXmlHttp.responseXML.getElementsByTagName('response'))
						{	
							var s_response = o_ajaxXmlHttp.responseXML.getElementsByTagName('response');
							var s_response_message = s_response[0].firstChild.nodeValue;
							if(s_response_message == 'Done')
							{
								window.location.href ='./message_site_engine.php';
								window.location.reload;
							}
							else
							{
								alert('what happen!?')
							}
						}		
					}
			}
						
	  	}

 	}
	return false;
}

f_addLoadEvent(f_getEvent);