//use with onkeypress event
function isnumeric(e)
{
    var keyNum;
    if(e.keyCode)
    {
        keyNum = e.keyCode;
    }
    else
    {
        keyNum = e.which
    }
    var keyChar = String.fromCharCode(keyNum);
    var regex = /\d|\t/
    return regex.test(keyChar)
}

function isReturn(e)
{
    var keyNum;
    if(e.keyCode)
    {
        keyNum = e.keyCode;
    }
    else
    {
        keyNum = e.which
    }
    var keyChar = String.fromCharCode(keyNum);
    var regex = /\r/
        
    return regex.test(keyChar)
}

function allowPostback(v) 
{
    if (!v && document.all) 
    {
        event.returnValue = false;
    }
    return v;
}