Calculate the caret(cursor) position

getCursorPosition.js

function getCursorPosition (inp) {
    if ("selectionStart" in inp) {
        return inp.selectionStart
    } else if (document.selection) {
        inp.focus();
        var sel = document.selection.createRange();
        var selLen = document.selection.createRange().text.length;
        sel.moveStart("character", -inp.value.length);
            return sel.text.length - selLen;
        }
}