jquery表情插入插件

[xjpphp]

插件代码如下：
(function($) {
$.fn.extend({
insertContent: function(myValue, t) {
var $t = $(this)[0];
if (document.selection) { //ie
this.focus();
var sel = document.selection.createRange();
sel.text = myValue;
this.focus();
sel.moveStart('character', -l);
var wee = sel.text.length;
if (arguments.length == 2) {
var l = $t.value.length;
sel.moveEnd("character", wee + t);
t < = 0 ? sel.moveStart("character", wee - 2 * t - myValue.length) : sel.moveStart("character", wee - t - myValue.length);
sel.select();
}
} else if ($t.selectionStart || $t.selectionStart == '0') {
var startPos = $t.selectionStart;
var endPos = $t.selectionEnd;
var scrollTop = $t.scrollTop;
$t.value = $t.value.substring(0, startPos) + myValue + $t.value.substring(endPos, $t.value.length);
this.focus();
$t.selectionStart = startPos + myValue.length;
$t.selectionEnd = startPos + myValue.length;
$t.scrollTop = scrollTop;
if (arguments.length == 2) {
$t.setSelectionRange(startPos - t, $t.selectionEnd + t);
this.focus();
}
}
else {
this.value += myValue;
this.focus();
}
}

})
})(jQuery);
IE下有个问题是：如果输入表情后如果鼠标点击到其他地方（即让文本框失去焦点），然后在插入表情表情字符就会在显示在前面，怎么修改插件 解决这个问题？演示地址http://www.css88.com/demo/insertContent/，冰天雪地跪求。

[fubiddt]

[fubiddt]