根据浏览器判断，来定位光标的位置：

通过$.browser.msie来判断是否是IE浏览器 

$(function() {
        $("#txt").click(function() {
            var position = 0;
            var txtFocus = document.getElementById("txt");
            if ($.browser.msie) {
                var range = txtFocus.createTextRange();
                range.move("character", position);
                range.select();
            }
            else {
                //obj.setSelectionRange(startPosition, endPosition);
                txtFocus.setSelectionRange(position, position);
                txtFocus.focus();
            }
        });
    });

js设置光标位置