function IsNumeric(strString)
    //  check for valid numeric strings	
    {
        var strValidChars = "0123456789.-";
        var strChar;
        var blnResult = true;

        if (strString.length == 0) return false;

        //  test strString consists of valid characters listed above
        for (i = 0; i < strString.length && blnResult == true; i++) {
            strChar = strString.charAt(i);
            if (strValidChars.indexOf(strChar) == -1) {
                blnResult = false;
            }
        }
        return blnResult;
    }

        function Validation()
        {


            var str = '';
            var testResult = true;
            var elem = document.getElementById('aspnetForm').elements;
            for (var i = 0; i < elem.length; i++) 
            {
                if (elem[i].type=='text')
                {
                    if (elem[i].name.indexOf("VariantCart") > 0) 
                    {

                        if (IsNumeric(elem[i].value) == false)
                        {
                            alert("Please enter a valid QUANTITY");
                            elem[i].focus();
                            testResult = false;
                            break;
                        }
                        if (elem[i].value <= 0) 
                        {
                            alert("please enter QUANTITY greater than 0");
                            elem[i].focus();
                            testResult = false;
                            break;
                        }
                        
                        if (elem[i].value > 99) {
                            alert("please enter QUANTITY less than 100");
                            elem[i].focus();
                            testResult = false;
                            break;
                        }

                    }
                }
            }

            return testResult;

        if (document.getElementById("ctl00$ContentPlaceHolder1$dgVariantCart$ctl02$txtQuantity").value <= 0) {
            alert("please enter QUANTITY greater than 0");
            document.getElementById("ctl00$ContentPlaceHolder1$dgVariantCart$ctl02$txtQuantity").focus();
            return false;
        }
        else if (IsNumeric(document.getElementById("ctl00$ContentPlaceHolder1$dgVariantCart$ctl02$txtQuantity").value) == false) {
            alert("Please enter a valid QUANTITY");
            document.getElementById("ctl00$ContentPlaceHolder1$dgVariantCart$ctl02$txtQuantity").focus();
            return false;
        }
        else if (document.getElementById("ctl00$ContentPlaceHolder1$dgVariantCart$ctl02$txtQuantity").value > 999) {
            alert("please enter QUANTITY less than 1000");
            document.getElementById("ctl00$ContentPlaceHolder1$dgVariantCart$ctl02$txtQuantity").focus();
            return false;
        }
    }