js获取文本框（或文本域）光标位置以及设置光标位置

var cursor = {
            /*获取文本框（或文本域）光标位置  ele:文本框（或文本域）*/
            getCursorPosition: function (element) {
                var pos = 0;
                if (document.selection) {/*IE*/
                    element.focus();
                    var range = document.selection.createRange();
                    range.moveStart("character", -form1.txt.value.length);
                    pos = range.text.length;
                } else if (element.selectionStart) {
                    pos = element.selectionStart;
                }
                return pos;
            },
            /*设置文本框（或文本域）光标位置  ele:文本框（或文本域），pos位置(可选，默认为0)*/
            setCursorPosition: function (element, pos) {
                pos = pos ? pos : 0;
                if (element.createTextRange) {
                    var range = element.createTextRange();
                    range.collapse(true);
                    range.moveEnd(‘character‘, pos);
                    range.moveStart(‘character‘, pos);
                    range.select();
                } else if (element.setSelectionRange) {
                    element.setSelectionRange(pos, pos);
                }
            }
        }