JS验证IP

用JavaScript 验证IP地址是否合法

function checkIP(){
    var startIP = $("#startIP").val();
    var endIP = $("#endIP").val();
    var exp=/^(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$/;
    var reg = startIP.match(exp);
    var reg2 = endIP.match(exp);
    if(reg == null){
        alert("开始的IP地址不合法！");
        return false;
    }else{
        if(reg2 == null){
            alert("结束的IP地址不合法！");
            return false; 
        }else{
            var compIP = compareIP(startIP,endIP);
            if(compIP == 1){
                return true;
            }else{
                alert("开始IP必须小于结束IP！");
                return false;
            }
        }
    }
}