Run some php Code with SAPUI5 on HANA Cloud Platform : I try to write some data with php in an .txt file. Therefore I create in my SAPUI5 App the file "writeData.php" with this content:

    <?php 
      $inhalt = "123456789";
      $handle = fopen ("testWrite.txt", w);
      fwrite ($handle, $inhalt);
      fclose ($handle);
    ?>
Then I try to call this file with the following Ajax request:

    writeStringToWhitelist: function(newContent){
		    $.ajax({
		        url: "writeData.php",
		        type: "POST",
		        data: newContent,
		        async: false,
		        success: function(){
		            console.log("Success");
		        }
		    });
		}

I know that there are surely some mistakes, but I hope someone can help me! 

Thanks in regards