function isValidEmail(obj) {
   str = obj.value;
   
   if (str.indexOf('.') < 1 && (str.indexOf('@') != 1)){
    alert ('Please enter a valid email address field');
    obj.value='';
    obj.focus();
   } 
}

function isInFilter(oneinput, digit)
{
    for (var oi=0;oi<oneinput.value.length;oi++)
    {
        var onechar=oneinput.value.substr(oi,1);
        if (digit.indexOf(onechar)==-1)
        {
            oneinput.value='';
            oneinput.focus();            
            return false;
        }
    }

    return true;
}


function isValidNumber (obj)
{    
    var digit='0123456789';
    if (!isInFilter (obj, digit))  {
        alert('Pleas supply a valid numeric field');
        return false;
    }
        
    return true;
}

function isValidMoney (obj)
{
    var digit='0123456789.,';
    if (!isInFilter (obj, digit)){
        alert ('Please supply a valid money field');
        return false;
    }
    return true;
}

function isValidPhone (obj)
{
    var digit='0123456789()-';
    if  (!isInFilter (obj, digit)){
        alert ('Please supply a valid phone number');
        return false;
    }
    
    return true;
}