var create_form = function (suggest_task_tags_url) {

  $(function() {

    function split( val ) {

      return val.split( /,\s*/ );

    }

    function extractLast( term ) {

      return split( term ).pop();

    }

    $( "#id_tags_field")

      // don't navigate away from the field on tab when selecting an item

      .bind( "keydown", function( event ) {

        if ( event.keyCode === $.ui.keyCode.TAB &&

            $( this ).data( "autocomplete" ).menu.active ) {

          event.preventDefault();

        }

      })

      .autocomplete({

        source: function( request, response ) {

          $.getJSON(suggest_task_tags_url, {

            term: extractLast( request.term )

          }, response );

        },

        search: function() {

          // custom minLength

          var term = extractLast( this.value );

          if ( term.length < 2 ) {

            return false;

          }

        },

        focus: function() {

          // prevent value inserted on focus

          return false;

        },

        select: function( event, ui ) {

          var terms = split( this.value );

          // remove the current input

          terms.pop();

          // add the selected item

          terms.push( ui.item.value );

          // add placeholder to get the comma-and-space at the end

          terms.push( "" );

          this.value = terms.join( ", " );

          return false;

        }

      });

  });

}