function validateCard(){
  var types=document.getElementsByName('cctype');
  var ccNumber=document.getElementById('cardnumber');
  var cvn=document.getElementById('cvn');
  var type="visa";
  for(var i=0;i<types.length;i++){
     if(types[i].checked){
	    type=types[i].value;
		break;
	 }
  }
     if(type=="visa"){
        if(ccNumber.value.length!=16||ccNumber.value.substring(0,1)!="4"){
		  alert("please input a valid Visa Card Number(16 digits).\n             4XXX XXXX XXXX XXXX");
		  return false;
		}
		if(cvn.value.length!=3){
		  alert("please input 3 digits CVN");
		  return false;
		}
     }else if(type=="master"){
        if(ccNumber.value.length!=16||ccNumber.value.substring(0,1)!="5"){
		  alert("please input a valid Master Card Number(16 digits).\n             5XXX XXXX XXXX XXXX");
		  return false;
		}
		if(cvn.value.length!=3){
		  alert("please input 3 digits CVN");
		  return false;
		}
     }else if(type=="express"){
	    if(ccNumber.value.length!=15||ccNumber.value.substring(0,1)!="3"){
		  alert("please input a valid American Express Card Number(15 digits).\n             3XXX XXXX XXXX XXX");
		  return false;
		}
		if(cvn.value.length!=4){
		  alert("please input 4 digits CVN.");
		  return false;
		}      
	 }else{
	     alert("Sorry,your card is not supporttd by our site!");
		 return false;
	 }
  return true;
}

function onlyNumber(e){
	var isIE = false;
	var isFF = false;
	var isSa = false;

	if ((navigator.userAgent.indexOf("MSIE")>0) && (parseInt(navigator.appVersion) >=4))isIE = true;
	if(navigator.userAgent.indexOf("Firefox")>0)isFF = true;
	if(navigator.userAgent.indexOf("Safari")>0)isSa = true;
    var key;
    iKeyCode = window.event?e.keyCode:e.which;
    if( !(((iKeyCode >= 48) && (iKeyCode <= 57))||(iKeyCode == 0)|| (iKeyCode == 8)))
    {   
        if (isIE)
        {
            e.returnValue=false;
        }
        else
        {
            e.preventDefault();
        }
    }
}

function helpCVN(){
   window.showModalDialog("/s/vcn.html");
}

var sFlag=0;

function switchImg(){
  var imgRef= document.getElementById('homeImg');
  if(imgRef!=null){
    if(sFlag==0){
		imgRef.src="../s/images/home_img_2.jpg";
		sFlag=1;
	}else{
	    imgRef.src="../s/images/home_img_1.jpg";
		sFlag=0;
	}
	setTimeout("switchImg()", 6000); 
  }
}

// transition image on /s/index.php

$(document).ready(function() {
	switchImg();
});