Inserting slider using php include

Hi I am trying to insert a slider in a file called ‘banner.html’. I am using artificer theme. the banner file is in /public_html/wp-content/themes/artificer/banner.html

and im using the code <?php include ‘banner.html’;?> but i keep getting the error message:
Warning: include(draft.html) [function.include]: failed to open stream: No such file or directory in …blah blah

any help hugely appreciated!