First plugin syntax error

I am trying to learn how to write a plugin.
I get a synatax error on line 53 which I cant fathom – unexpected ‘
Any help appreciated
,
<?php
//Add my_plugin hook
function my_plugin(){
do_action(‘my_plugin’);
}

function input_form_handler(){
$form_output=input_form();
return $form_output;
}

function input_form(){
$form_output=”Hello World”;
return $form_output;
}
add_action(‘my_plugin’,’input_form_handler’);

//add admin panel
add_action(‘admin_menu’,’my_plugin_admin_actions’);

function my_plugin_admin_actions(){
add_options_page(‘Author Data Edit’,’Author Data Edit’,1,);
}

?>
‘