function checkLogin() {
        
		var errmsg = "";
		var errobj = null;
		var i=0, j=0, an=20;
		
	    var ckb = document.getElementsByName('checkbox');
		   for(i=0;i<ckb.length;i++){
				if(ckb[i].checked==true) {
					j++;
				}
		   }
		    if(j!=an){
					errmsg += ""+j+" item(s) ticked，must tick "+an+" items!\n";
			}
		  
		if (document.getElementById('textfield').value == 0) {
			errmsg += "Please enter name!\n";
			if (errobj==null) errobj = document.getElementById('textfield');
		}	 

		if (document.getElementById('textfield2').value == 0) {
			errmsg += "Please enter NRIC number!\n";
			if (errobj==null) errobj = document.getElementById('textfield2');
		}
		
		if (document.getElementById('textfield3').value == 0) {
			errmsg += "Please enter Star Card number!\n";
			if (errobj==null) errobj = document.getElementById('textfield3');
		} else {
			var s = document.getElementById('textfield3').value;
			if (s.substring(0,4)=="4201" && s.length==11) {
			} else if (s.substring(0,4)=="4202" && s.length==11) {
			} else {
				errmsg += "You have entered an invalid Star Card number, pls try again!\n";
				if (errobj==null) errobj = document.getElementById('textfield3');
			}
		}

		var vao = document.getElementById('textfield4');
		var val = vao.value;
		if (val == 0) {
			errmsg += "Please enter date of birth!\n";
			if (errobj==null) errobj = vao;
		} else {
		    var red = /^[0-9]{4}\/[0-1][0-9]\/[0-3][0-9]$/;
			if(!red.test(val)){
				errmsg += "Please enter a valid date!\n";
				if (errobj==null) errobj = vao;
			}

		}

		var con = 0;

		vao = document.getElementById('textfield6');
		val = vao.value;
		if (val == 0 ) {
		} else {
			var ret = /^[0-9]{8}$/;
			if(!ret.test(val)){
				errmsg += "Please enter 8-digit mobile number!\n";
				if (errobj==null) errobj = vao;		 
			} else {
				con++;
			}
		}

		vao = document.getElementById('textfield7');
		val = vao.value;
		if (val == 0 ) {
		} else {
			var ret = /^[0-9]{8}$/;
			if(!ret.test(val)){
				errmsg += "Please enter 8-digit home number!\n";
				if (errobj==null) errobj = vao;		 
			} else {
				con++;
			}
		}

		vao = document.getElementById('textfield8');
		val = vao.value;
		if (val == 0 ) {
		} else {
			var ret = /^[0-9]{8}$/;
			if(!ret.test(val)){
				errmsg += "Please enter 8-digit office number!\n";
				if (errobj==null) errobj = vao;		 
			} else {
				con++;
			}
		}

		if (con<1) {
			errmsg += "Please enter at least one contact number!\n";
			if (errobj==null) errobj = document.getElementById('textfield6');
		}
		
		if (document.getElementById('textfield9').value == 0) {
			errmsg += "Please enter email address!\n";
			if (errobj==null) errobj = document.getElementById('textfield9');
		} else {
		    var ree = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
			if (!ree.test(document.getElementById('textfield9').value)) {
				errmsg += "Please enter a valid email address!\n";
				if (errobj==null) errobj = document.getElementById('textfield9');
			}
		}
		
		
//		if (document.getElementById('textfield10').value == 0) {
//			errmsg += "Please enter address!\n";
//			if (errobj==null) errobj = document.getElementById('textfield10');
//		}

		if (document.getElementById('textfield11').value == 0 || document.getElementById('textfield11').value!=document.getElementById('acode').innerHTML) {
			errmsg += "Please enter code shown!\n";
			if (errobj==null) errobj = document.getElementById('textfield11');
		}
		
		if (!document.getElementById('checkbox31').checked) {
			errmsg += "terms\n";
			if (errobj==null) errobj = document.getElementById('checkbox31');
		}
		
		if (errmsg.length>0) {
			alert(errmsg);
			if (errobj!=null) {
				errobj.focus();
				if (errobj.select) errobj.select();
			}
			return false;
		}
		return true;	
    }
	
		function submitRegister() {
	
		if (!checkLogin()) return;
		
		var answer = "";
		
		for(k=1;k<31;k++){
			var g = document.getElementById("checkbox"+ k);	
			if(g.checked){
				 answer  += g.value +",";
			}
		}

		var s = "name=" + document.getElementById("textfield").value;
		s += "&nric_number=" + document.getElementById("textfield2").value;
		s += "&card_number=" + document.getElementById("textfield3").value;
		s += "&birthday=" + document.getElementById("textfield4").value;
		s += "&contact_number=" + document.getElementById("textfield5").value;
		s += "&mobile=" + document.getElementById("textfield6").value;
		s += "&home=" + document.getElementById("textfield7").value;
		s += "&office=" + document.getElementById("textfield8").value;
		s += "&email=" + document.getElementById("textfield9").value;
		s += "&address=" + document.getElementById("textfield10").value;
		s += "&code_shown=" + document.getElementById("textfield11").value;
		s += "&answer=" + answer;
		
        document.getElementById('main-form').innerHTML = post("thankyou.aspx", s);
		
		setTimeout(function(){
			window.location.href="http://www.toysrus.com.sg";
		}, 10000);
	}
	
	function http () {
	var req;
   	if (window.XMLHttpRequest) {
   	    req = new XMLHttpRequest();
   	} else if (window.ActiveXObject) {
		req = new ActiveXObject("Microsoft.XMLHTTP");
    } else {
		req = null;
        alert("xmlhttprequest not supported");
	}
	return req;
}

function post(u, c) {
	var q = http();
	var l = u.match(/\?/) ? u + '&_=' : u + '?_=';
	l += Math.random();
	q.open('POST', l, false);
	q.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	q.send(c);
	return q.responseText;
}