$str = $info[5];
if ( strtolower(substr($str, 0, 4)) == "http" )
echo "<a href=$str target=_blank>";
else
echo "<a href='invalid.htm' target=_blank>";invalid.htm 是告诉用户“页面无效”信息的页面
或者
echo "<a href="#" target=_blank onclick=\"alert('链接无效');\">";
if ( strtolower(substr($str, 0, 4)) == "http" )
echo "<a href=$str target=_blank>";
else
echo "<a href='invalid.htm' target=_blank>";invalid.htm 是告诉用户“页面无效”信息的页面
或者
echo "<a href="#" target=_blank onclick=\"alert('链接无效');\">";
if (substr($str,0,4) == "http")
echo $str;
else echo "#";
$str = $info[5];
if (substr($str,0,4) == "http")
echo $str;
else echo "#";
?>" target="_blank">
if(ereg("^http.+",$info[5])) {
print "把他做成链接";
}else {
print "这个无效";
}
?>判断已经给你做完了.具体的你加就可以了.