window.onload = function () {

  //  var input = document.getElementById("ff.aa");

​

    $(".aa").onkeypress = function () {

        // So that things work both on Firefox and Internet Explorer.

        var evt = arguments[0] || event;

        var char = String.fromCharCode(evt.which || evt.keyCode);

​

        // Is it a lowercase character?

        if (/[a-z]/.test(char)) {

            // Append its uppercase version

            input.value += char.toUpperCase();

​

            // Cancel the original event

            evt.cancelBubble = true;

            return false;

        }

    };

};