flashvenom

Hi There I am trying to to simply declare an id with an echo inside and then replace the string, if that makes sense. The issue is clearly with the first line of code This works $str1 = "myimage.jpg" <img src="<?php print preg_replace("/\.jpg$/i","-313x174.jpg",$str1);?>"/> output = myimage-313x174.jpg This doesnt $str1 = "<?php the_field('grid_tile_one'); ?>" <img src="<?php print preg_replace("/\.jpg$/i","-313x174.jpg",$str1);?>"/> Any help much appreciated.