function validate(){
var str_mail=document.form_email.Email.value
alert_str=0;
		
		if (str_mail==""){
			alert_str="You have not written down your Email address"
		}else{
			if (str_mail.indexOf("@",0)<=0 || str_mail.indexOf(".",0)<=0){
			alert_str="The Email address is not correct"
			}
		}
		
		if (document.form_email.Contact_Person.value==""){
			alert_str="You have not written down your Name"		
		}		
		
		if (document.form_email.Phone_No.value==""){
			alert_str="You have not written down your Telphone number"		
		}
				
		if (alert_str!=0){
			alert(alert_str);
			event.returnValue=false;
		}
	}
	
function clear_check_value(){
	document.form_email.Products[0].checked=false;
	document.form_email.Products[1].checked=false;
	document.form_email.Products[2].checked=false;
	document.form_email.Products[3].checked=false;
}	
	
var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		pic = newImage("images/menu_about_en.gif");

		preloadFlag = true;
	}
}


function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

function changeTable(pic_num,pic_dir) {
	if (pic_dir<0){
		pic_num=pic_num-1}
	else{
		pic_num=pic_num+1}
}