function include(file)  
 {  
   
   var script  = document.createElement('script');  
   script.src  = file;  
   script.type = 'text/javascript';  
   script.defer = true;     

   document.getElementsByTagName('head').item(0).appendChild(script);  
   
 }  


function getXMLHttp()
{
  var xmlHttp

  try
  {
    //Firefox, Opera 8.0+, Safari
    xmlHttp = new XMLHttpRequest();
  }
  catch(e)
  {
    //Internet Explorer
    try
    {
      xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch(e)
    {
      try
      {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch(e)
      {
        alert("Your browser does not support AJAX!")
        return false;
      }
    }
  }
  return xmlHttp;
}


function ChangePage(page)
{

ShowLoader();

  var xmlHttp = getXMLHttp();
 
  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      HandleResponse(xmlHttp.responseText);
    }
  }

  
   
  Cbtns(page);
  
   
  switch(page){
 
				case 'home': 
						xmlHttp.open("GET", "home.php", true);
						document.getElementById('menu_home').setAttribute("class", "selected");			
						
						break;
				case 'projects': 
						xmlHttp.open("GET", "projects.php", true);
						document.getElementById('menu_projects').setAttribute("class", "selected");
						break;		
						
						case 'projects-games': 
								xmlHttp.open("GET", "projects-games.php", true);
								document.getElementById('menu_projects').setAttribute("class", "selected");
								break;							
						case 'projects-tenders': 
								xmlHttp.open("GET", "projects-tenders.php", true);
								document.getElementById('menu_projects').setAttribute("class", "selected");
								break;						
						
				case 'partners': 
						xmlHttp.open("GET", "partners.php", true);
						document.getElementById('menu_partners').setAttribute("class", "selected");	
						break;		
				case 'contact': 
						xmlHttp.open("GET", "contact.php", true);
						document.getElementById('menu_contact').setAttribute("class", "selected");	
						break;		
				case 'about': 
						xmlHttp.open("GET", "about.php", true);
						document.getElementById('menu_about').setAttribute("class", "selected");	
						break;	
				default:
						xmlHttp.open("GET", "home.php", true);
						document.getElementById('menu_home').setAttribute("class", "selected");
					break;
			}
  
  xmlHttp.send(null);
}

function HandleResponse(response)
{
  document.getElementById('page').innerHTML = response;

  
  
}

function Cbtns(page)
{
  document.getElementById('menu_home').setAttribute("class", "");
  document.getElementById('menu_projects').setAttribute("class", "");
  document.getElementById('menu_partners').setAttribute("class", "");
  document.getElementById('menu_contact').setAttribute("class", "");
  document.getElementById('menu_about').setAttribute("class", "");
}


function ShowLoader()
{
  document.getElementById('page').innerHTML = "<div id='loader'><img src='ajax-loader.gif' alt='loading...'/></div>";
}



function validEmail(string){
		if(!string) return false;
		string = string.toLowerCase();
		urlRegExp = /^[a-z0-9_\+-]+(\.[a-z0-9_\+-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*\.([a-z]{2,4})$/
		return urlRegExp.test(string);
}

function validNum(string){
		if(!string) return false;
		string = string.toLowerCase();
		urlRegExp = /^[0-9]+$/
		return urlRegExp.test(string);
}


function txt_change()
{

var validit=1;

if (validEmail(document.getElementById("txtEmail").value))
	{//document.getElementById("txtEmail").style.border="1px solid green";
	document.getElementById("EmailPic").src="images/ok.jpg";
	}else{
	//document.getElementById("txtEmail").style.border="1px solid red";
	document.getElementById("EmailPic").src="images/fl.gif";
	validit=0;
	}

if (document.getElementById("txtName").value!="")
	{//document.getElementById("txtName").style.border="1px solid green";
	document.getElementById("NamePic").src="images/ok.jpg";
	}else{
	//document.getElementById("txtName").style.border="1px solid red";
	document.getElementById("NamePic").src="images/fl.gif";
	validit=0;
	}
	
if (document.getElementById("txtSubject").value!="")
	{//document.getElementById("txtSubject").style.border="1px solid green";
	document.getElementById("SubjectPic").src="images/ok.jpg";
	}else{
	//document.getElementById("txtSubject").style.border="1px solid red";
	document.getElementById("SubjectPic").src="images/fl.gif";
	validit=0;
	}
	
	if (document.getElementById("txtMessage").value!="")
	{//document.getElementById("txtMessage").style.border="1px solid green";
	document.getElementById("MessagePic").src="images/ok.jpg";
	}else{
	//document.getElementById("txtMessage").style.border="1px solid red";
	document.getElementById("MessagePic").src="images/fl.gif";
	validit=0;
	}
	
if (validNum(document.getElementById("txtCaptcha").value))
	{//document.getElementById("txtCaptcha").style.border="1px solid green";
	document.getElementById("CaptchaPic").src="images/ok.jpg";
	}else{
	//document.getElementById("txtCaptcha").style.border="1px solid red";
	document.getElementById("CaptchaPic").src="images/fl.gif";
	validit=0;
	}
	
		
	switch (validit){
		case 1:
					document.getElementById("contact_submit").disabled="";
					break;
		case 0:
					document.getElementById("contact_submit").disabled="true";
					break;
					
	}


	
	}