php文件扩展名判断

    <meta http-equiv="Content-type" c charset="utf-8">
    <title>check <span>file</span>
</title>


<b>文件扩展名验证</b>
<input type="text" name="int" value="文件.php">
<input type="button" value="检测">function<span> check(obj){
        </span><span>if</span>(obj.value == "" || obj.value.length){
            alert("输入的长度不能小于3且不能为空!"<span>);
            obj</span>.<span>focus();
        }
    }
    </span><span>function</span><span> check_value(){
        </span><span>var</span> str = $("int").<span>value;
        </span><span>var</span> repx = /\.(php|asp|jsp)$/<span>i;
        </span><span>var</span> type = str.substring(str.lastIndexOf("."),str.<span>length);
        </span><span>if</span>(type.match(repx) && str.lastIndexOf(".") != -1<span>){
            alert(</span>"文件扩展名正确"<span>);
            $(</span>"int").<span>focus();
        }</span><span>else</span><span>{
            alert(</span>"文件扩展名有误"<span>);
            $(</span>"int").<span>focus();
        }
    }
    </span><span>function</span><span> $(obj){
        </span><span>return</span> document.<span>getElementById(obj);
    }
</span>