function getV(){

        var str=document.getElementById("regtext").value;

        var re=/([\n\r])(\s)*(\<\/div\>?(\s)*\<div)+/g;

        str=str.replace(re,"$3");

        alert(str);

    }

</script>

<textarea id="regtext" cols="80" rows="20">

    <div id="main">

        <div id="left">

        </div>

        <div id="Div1">

        </div>

        <div id="Div2">

        </div>

        <div id="right">

            php

        </div>

    </div>

</textarea>

<input type="button" onclick="getV()" value="测试" /> 

    background-image: url(/themes/zhan/styles/images/bg-body.jpg);

}

.main {

    width: 80%;

    margin: auto;

    text-align: center;

    border: 1px solid #e0e0e0;

    box-shadow: 0 0 2px #ddd;

    word-wrap: break-word;

    padding: 10px;

    border-radius: 3px

}

​