<html>
<head>
<title>Template </title>
<script language="javascript">
<!--
function age_average()
{
var temp
temp = "[img1]";
document.form1.t5.value += temp;
}
//-->
</script>
</head>
<body>
<center>
<form name=form1 method="name" action="" >
<input type="button" value="插入码证码" name="B6" onClick="age_average()">
<img src="obscene/testabc/poor.gif" alt="哈哈" width="24" height="24" onClick="age_average()">
<input type="text" name="t5" size="20"> </p>
</form>
</center>
</body>
</html>
给你段代码
<body>
<script language="JavaScript">
function cc(a)
{
form1.username.focus();
var s=document.selection.createRange();
s.setEndPoint("StartToStart",form1.username.createTextRange());
var l=s.text.length;
alert("光标所在伴置:"+l);
var str=form1.username.value.substring(0,l)+a+form1.username.value.substring(l,form1.username.value.length);
form1.username.value=str;
alert("在光标中间新增字符:"+a);
}
</script>
<form name="form1" method="post" action="">
<p>
<input name="username" type="text" id="username" value="123456789" size="50">
</p>
<p>
<input type="button" name="Submit" value="测试" onclick='cc("test")'>
</p>
</form>
</body>