function mod10Check(custId) {
	
	var validity = false;
			
	if (custId.length == 15 || custId.length == 16 || custId.length == 9) {				
		if ((custId.length == 15 && (custId.slice(0,6).indexOf('33303') != -1 || custId.slice(0,6).indexOf('22201') != -1 || custId.slice(0,6).indexOf('99222') != -1 || custId.slice(0,6).indexOf('99200') != -1 || custId.slice(0,6).indexOf('99990') != -1)) || (custId.length == 16 && (custId.slice(0,6).indexOf('403400') != -1 || custId.slice(0,6).indexOf('401000') != -1 || custId.slice(0,6).indexOf('401001') != -1 || custId.slice(0,6).indexOf('401002') != -1 || custId.slice(0,6).indexOf('401003') != -1 || custId.slice(0,6).indexOf('523400') != -1 || custId.slice(0,6).indexOf('531000') != -1 || custId.slice(0,6).indexOf('531001') != -1 || custId.slice(0,6).indexOf('531002') != -1 || custId.slice(0,6).indexOf('531003') != -1)) || (custId.length == 9)) {				
			checkDigit = custId.charAt(custId.length-1);
					
			digits = new Array();
					
			for (i=0; i<custId.length-1; i++)
				digits.push(custId.charAt(i));		
					
			digits.reverse();
							
			m = 2;
			checkValue = new Array();
						
			for (i=0; i<digits.length;i++) {
				checkValue.push(m*digits[i]);
	
				if (m == 2) {
					m = 1
				} 
				else {
					m = 2
				}	
			}
					
			for (i=0; i<checkValue.length; i++)
				if (checkValue[i]>9) {
					checkValue[i] = checkValue[i]+'';
					checkValue[i]=parseInt(checkValue[i].charAt(0))+parseInt(checkValue[i].charAt(1));
				}
					
			res = 0;
			for (i=0; i<checkValue.length; i++)
				res = res + checkValue[i];
					
			res = Math.ceil(res/10)*10 - res;
					
			if (res == checkDigit) {
				validity = true;	
			} 
		}  
	}  
if (validity == false){alert("卡号错误！");document.instant_form.instant_no.focus();}
else if(trim(document.instant_form.ycode.value)=="")
	{
		alert("请输入验证码!");
		document.instant_form.ycode.focus();
		validity=false;
	}

	return validity;
}