Someone

 1 <?php
 2 $blah = getimagesize("/home/diego/tux.png");
 3 if ($blah[0] < 100 && $blah[1] < 100)
 4 {
 5 echo "width: $blah[0]\nheight: $blah[1]";
 6 }
 7 else
 8 {
 9 echo "the image is big, please resize it.";
10 }