在图像上添加文本时出现php错误

Hello am a newbie in php, so i dont have much knowledge about that. I am trying to add text over image with form method but that doesnt works Here are the codes

In form-add-text.php

 <form id="action-meme" action="mysite.com/image-process.php/">

<input name="cp" id="inputcpname" type="text" >
<input type="submit" >
</form>

Here is the code in image-process.php

  <?php
  //Set the Content Type
  header('Content-type: image/jpeg');

  // Create Image From Existing File
 $jpg_image = imagecreatefromjpeg('http://i.imgur.com/xxxYpW.jpg');

  // Allocate A Color For The Text
   $white = imagecolorallocate($jpg_image, 255, 255, 255);

  // Set Path to Font File
 $font_path = 'http://fonts.googleapis.com/css?family=Gabriela';

 // Set Text to Be Printed On Image
 $text = $_POST["cp"];

 // Print Text On Image
  imagettftext($jpg_image, 25, 0, 75, 300, $white, $font_path, $text);

 // Send Image to Browser
 imagejpeg($jpg_image);

 // Clear Memory
 imagedestroy($jpg_image);
?>

BUt if i replace "$_POST["cp"]" with some text it works well

I am unable to figure out my work

Try adding method to the form

 <form id="action-meme" action="mysite.com/image-process.php/" method="post">

add method="post" in form

 <form id="action-meme" action="mysite.com/image-process.php/" method="post" >

<input name="cp" id="inputcpname" type="text" >
<input type="submit" >
 </form>