Reigel's demo page

HTML

<input ID="btnClear" onkeydown="return goToFirst();"/>

CSS

.allowed {
    text-decoration: none;
}
.disallowed {
    text-decoration: line-through;
}

JavaScript

function goToFirst(evt) {
    var e = event || evt; // for trans-browser compatibility
    var charCode = e.which || e.keyCode;
    
    alert(charCode);
    if (charCode == 9 ) {
        document.getElementById('txtFirstName').focus();
        document.getElementById('txtFirstName').select();
    }
    
    return false;
};