No numbers allowed in textbox in Javascript.

 This script is very useful most specially if we want no numeric characters to be inputed in our textbox, and so, to eliminate those numeric keys, just simply use this script. Thanks to the original author of this script.

function blockNonNumbers(obj, e, allowDecimal, allowNegative)
{
    var key;
    var isCtrl = false;
    var keychar;
    var reg;
       
    if(window.event) {
        key = e.keyCode;
        isCtrl = window.event.ctrlKey
    }
    else if(e.which) {
        key = e.which;
        isCtrl = e.ctrlKey;
    }
   
    if (isNaN(key)) return true;
   
    keychar = String.fromCharCode(key);
   
    // check for backspace or delete, or if Ctrl was pressed
    if (key == 8 || isCtrl)
    {
        return true;
    }

    reg = /\d/;
    var isFirstN = allowNegative ? keychar == '-' && obj.value.indexOf('-') == -1 : false;
    var isFirstD = allowDecimal ? keychar == '.' && obj.value.indexOf('.') == -1 : false;
   
    return isFirstN || isFirstD || reg.test(keychar);
}

/*This script is running and tested by me personally.
*/