弄了个检测传输的参数是否为数字的Function

function checknum($id,$say)  
{  
            $inid=$id;  
            if(!ereg("^(-{0,1}|\+{0,1})[0-9]+(\.{0,1}[0-9]+)$",$inid))  
        {  
        echo $say.",入口:"."<font color=red>".$inid."</font>";  
            exit;  
        }  
}  

<?php  
$tid="111fff";  
checknum($tid,"数字非法")  
?>