How about
if(isset($var5)){
echo "$VAR4\n<br>email\n";
echo "<AHREF='mailto:$VAR5'>$VAR5</A>url:\n";
}
or Maybe
if(strlen($var5) > 1){
echo "$VAR4\n<br>email\n";
echo "<AHREF='mailto:$VAR5'>$VAR5</A>url:\n";
}
or Possibly
if($var5 != ""){
echo "$VAR4\n<br>email\n";
echo "<AHREF='mailto:$VAR5'>$VAR5</A>url:\n";
}