JQuery在光标位置插入内容的实现代码

(function($){
$.fn.extend({
insertAtCaret:function(myValue){
var$t=$(this)[0];
if(document.selection){
this.focus();
sel=document.selection.createRange();
sel.text=myValue;
this.focus();
}
else
if($t.selectionStart||$t.selectionStart=="0"){
varstartPos=$t.selectionStart;
varendPos=$t.selectionEnd;
varscrollTop=$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;
}
else{
this.value+=myValue;
this.focus();
}
}
})
})(jQuery);