Yo mismo me respondo, para los que busquen lo mismo que ya encontre un ejemplo.
Código PHP:
<?php Function Verifpost ($post)
{
$temp = $post;
$temp = preg_replace("/(\015\012)|(\015)|(\012)/","",$temp);
$temp = strtolower($temp);
$lg = strlen($temp);
for ( $i=0 ; $i<$lg ; $i++)
{
if ( ($temp[$i])== " " ) // si espace
{
for ( $j = $i ; $j < $lg ; $j++)
$temp[$j] = $temp[$j+1];
$lg-- ;
$i-- ;
}
}
if (ereg ( "table>" , $temp) or ereg ( "tr>",$temp) or ereg ("td>",$temp) or
ereg("script>",$temp) or ereg("meta>",$temp) or ereg("frame>",$temp) or
ereg("iframe>",$temp) or ereg("style>",$temp) or ereg("form>",$temp) or
ereg("input>",$temp) or ereg("select>",$temp) or ereg("div>",$temp) or
ereg("layer>",$temp) or ereg("option>",$temp) or ereg("body>",$temp) or
ereg("html>",$temp) or ereg("onclick",$temp) or ereg("<img",$temp) or
ereg("src>",$temp) or ereg("object>",$temp) or ereg("<applet",$temp) or
ereg ( "<table" , $temp) or ereg ( "<tr",$temp) or ereg ("<td",$temp) or
ereg("<script",$temp) or ereg("<meta",$temp) or ereg("<frame",$temp) or
ereg("<iframe",$temp) or ereg("<style",$temp) or ereg("<form",$temp) or
ereg("<input",$temp) or ereg("<select",$temp) or ereg("<div",$temp) or
ereg("<layer",$temp) or ereg("<option",$temp) or ereg("<body",$temp) or
ereg("<html",$temp) or ereg("onclick",$temp) or ereg("<src",$temp) or
ereg("<object",$temp) or ereg("applet>",$temp) )
return (false) ;
else
return (true) ;
}
?>