TextBox accept float only

Sample javascript code for TextBox that accept float only.

by manoj2010

HTML

<script>
function removeCommas(nStr) {
    if (nStr == null || nStr == "")
        return ""; 
    return nStr.toString().replace(/,/g, "");
}

function NumbersOnly(myfield, e, dec,neg)
{        
    if (isNaN(removeCommas(myfield.value)) && myfield.value != "-") {
        return false;
    }
    var allowNegativeNumber = neg || false;
    var key;
    var keychar;

    if (window.event)
        key = window.event.keyCode;
    else if (e)
        key = e.which;
    else
        return true;
    keychar = String.fromCharCode(key);
    var srcEl = e.srcElement ? e.srcElement : e.target;    
    // control keys
    if ((key == null) || (key == 0) || (key == 8) ||
                (key == 9) || (key == 13) || (key == 27))
        return true;

    // numbers
    else if ((("0123456789").indexOf(keychar) > -1))
        return true;

    // decimal point jump
    else if (dec && (keychar == ".")) {
        //myfield.form.elements[dec].focus();
        return srcEl.value.indexOf(".") == -1;        
    }

    //allow negative numbers
    else if (allowNegativeNumber && (keychar == "-")) {    
        return (srcEl.value.length == 0 || srcEl.value == "0.00")
    }
    else
        return false;
}
</script>
<input name="txtDiscountSum" type="text" onKeyPress="return NumbersOnly(this, event,true)" />