function submitSearchForm() {

    var searchvalue = document.getElementById('bitTextboxSearch').value;
    var forwardurl = document.getElementById('forwardurl').value;
    location.href = forwardurl + '?search=' + searchvalue;
}

function checkEnter(e) {
    var characterCode; //literal character code will be stored in this variable

    if (e && e.which) { //if which property of event object is supported (NN4)
        e = e
        characterCode = e.which //character code is contained in NN4's which property
    }
    else {
        e = event
        characterCode = e.keyCode //character code is contained in IE's keyCode property
    }

    if (characterCode == 13) { //if generated character code is equal to ascii 13 (if enter key)
        submitSearchForm();
    }
}