function MM_preloadImages() { //v2.0
  	if (document.images) {
	    var imgFiles = MM_preloadImages.arguments;
	    if (document.preloadArray==null) document.preloadArray = new Array();
	    var i = document.preloadArray.length;
	    with (document) for (var j=0; j<imgFiles.length; j++) if (imgFiles[j].charAt(0)!="#"){
	      preloadArray[i] = new Image;
	      preloadArray[i++].src = imgFiles[j];
  		}
  	}
	}

	 MM_preloadImages(
	 '/images/bg_main.jpg',
	 '/images/bg_con_top.png',
	 '/images/bg_con_middle.png',
	 '/images/bg_con_bottom.png',
	 '/images/bg_main_lb.jpg',
	 '/images/menu_01_on.gif',
	 '/images/menu_02_on.gif',
	 '/images/menu_03_on.gif',
	 '/images/menu_04_on.gif',
	 '/images/menu_05_on.gif',
	 '/images/menu_01.gif',
	 '/images/menu_02.gif',
	 '/images/menu_03.gif',
	 '/images/menu_04.gif',
	 '/images/menu_05.gif'
	 );
	 
	function chk_form(){
		var form=document.contact_us;
		if(form.fname.value==""){
		  alert("Please input your First Name.");
		  form.fname.focus();
		}else if(form.lname.value==""){
		  alert("Please input your Last Name.");
		  form.lname.focus();
		}else if(form.phone.value==""){
		  alert("Please input your Phone number.");
		  form.phone.focus();
		}else if(form.email.value==""){
		  alert("Please input your Email address.");
		  form.email.focus();
		}else if(form.subject.value==""){
		  alert("Please input subject.");
		  form.subject.focus();
		}else if(form.message.value==""){
		  alert("Please input message.");
		  form.message.focus();
		 
		}else{
		  form.submit();
		}
	}