I have problem with auto tabbing on Iphone or android. This auto tabbing code work perfectly on each browser of pc but not on mobile. please help me. its urgent.

$(document).ready(function() { WireAutoTab('<%= PartOne.ClientID %>', '<%= PartTwo.ClientID %>', 3); WireAutoTab('<%= PartTwo.ClientID %>', '<%= PartThree.ClientID %>', 2); });

function WireAutoTab(CurrentElementID, NextElementID, FieldLength) {
    //Get a reference to the two elements in the tab sequence.
    var CurrentElement = $('#' + CurrentElementID);
    var NextElement = $('#' + NextElementID);

    CurrentElement.keyup(function(e) {
        //Retrieve which key was pressed.
        var KeyID = (window.event) ? event.keyCode : e.keyCode;

        //If the user has filled the textbox to the given length and
        //the user just pressed a number or letter, then move the
        //cursor to the next element in the tab sequence.   
        if (CurrentElement.val().length >= FieldLength
        && ((KeyID >= 48 && KeyID <= 90) ||
        (KeyID >= 96 && KeyID <= 105)))
            NextElement.focus();

    });
}