Online PHP editor | output for abSc3

<?php $str="<!doctype html> <html> <head> <title>My Calculator</title> </head> <body align="center"> <b> MY CALCULATOR</b> <table border="0" cellpadding="3" cellspacing="0" align="center"> <tr><td> <form method="POST" action=""> <label for="First number"> First number:</label> </td> <td> <inputtype="text"name="first_num" maxlength="20"/> </td> </tr> <br/> <tr> <td> <label for="Second number"> Second number:</label> </td> <td><input type="text" name="sec_num" maxlength="20"/></td> </tr> <br/> <tr> <td> <input type="submit" name="opt" value="+"/>   <input type="submit" name="opt" value="-"/> </td><td> <input type="submit" name="opt" value="*"/>   <input type="submit" name="opt" value="/"/>   <input type="reset" value="RESET"</td> </form> </tr> </table> </body> </html>"; echo htmlentities($str); ?>