FormValidation need help V2

<script type="text/javascript">
function formValidator(){
    var Two = document.getElementById('Two');//Category
    var Total = document.getElementById('Total');//Category
    var ExVAT = document.getElementById('ExVAT');//exVAT
    var AmtPaid = document.getElementById('AmtPaid');

    if(Multiply(Two, Total, "Total Amt must be double the first amount", "The first calculation is correct, click OK for 2nd calculation"  )){
        if(isVAT(ExVAT, AmtPaid,  "incorrect or validation not working correctly", "YES! Correct!")){
                return true;
        }
    }
return false;
}
 // if (val1 != "" && val2 != "")

function Multiply(elem, elem2, helperMsg, correctMsg){
    if((elem2.value) == (elem.value*2)){
        alert(correctMsg);
        return true;
    }else{
        alert(helperMsg);
        elem.focus();
        return false;
    }
}
function isVAT(elem, elem2, helperMsg, correctMsg){
    if((elem2.value) == (elem.value*1.14)){
        alert(correctMsg);
        return true;

    }else{
        alert(helperMsg);
        elem.focus();
        return false;
    }
}


</script>
<form  action="alert('Correct!');"  onsubmit="return formValidator()" >
This one works:<br>
<input type="text" id="Two" name="Two" value="2"> *  2 =
<input type="text" id="Total" name="Total" value="4">
<br><br>

but this validation does not work:<br><br>


eg. R100 ex VAT = R114incl VAT<br>

Ex VAT: <input type="text" id="ExVAT" size = 7 name="ExVAT" value="10"><br>
*1.14 = <br>
AmtPaid: <input type="text" id="AmtPaid" name="AmtPaid" value="11.4">
<br>
<br>

<input type="submit" value="Submit/Save"  onsubmit='return formValidator()'  style="width:300px;height:30px" />
</form>
</body>
</html>