diff --git a/invitations.php b/invitations.php
index 01edcba..1096bfd 100644
--- a/invitations.php
+++ b/invitations.php
@@ -26,7 +26,7 @@ require_once("../../config.php");
 require_once($CFG->libdir.'/weblib.php');
 require_once($CFG->dirroot.'/grade/querylib.php');
 
-$invitedurl = "/local/treestudyplan/invited.php";
+$invitedurl = "{$CFG->wwwroot}/local/treestudyplan/invited.php";
 
 $systemcontext = context_system::instance();
 
@@ -97,16 +97,16 @@ if (!get_config("local_treestudyplan", "enableplansharing")) {
             print "<a class='m-action-resend m-action-confirm'";
             print " data-confirmtext='".get_string('invite_confirm_resend', 'local_treestudyplan', $invite->name)."'";
             print " data-confirmbtn='".get_string('send', 'local_treestudyplan')."'";
-            print " href='#' data-actionhref='edit-invite.php?resend={$invite->id}' title='"
+            print " href='#' data-actionhref='{$CFG->wwwroot}/local/treestudyplan/edit-invite.php?resend={$invite->id}' title='"
                     .get_string('invite_tooltip_resend', 'local_treestudyplan')."'";
             print " ><i class='fa fa-envelope'></i></a>";
 
-            print "<a href='edit-invite.php?update={$invite->id}'><i class='fa fa-pencil' title='"
+            print "<a href='{$CFG->wwwroot}/local/treestudyplan/edit-invite.php?update={$invite->id}'><i class='fa fa-pencil' title='"
                     .get_string('invite_tooltip_edit', 'local_treestudyplan')."'></i></a>";
             print "<a class='m-action-delete m-action-confirm'";
             print " data-confirmtext='".get_string('invite_confirm_delete', 'local_treestudyplan', $invite->name)."'";
             print " data-confirmbtn='".get_string('delete')."'";
-            print " href='#' data-actionhref='edit-invite.php?delete={$invite->id}' title='"
+            print " href='#' data-actionhref='{$CFG->wwwroot}/local/treestudyplan/edit-invite.php?delete={$invite->id}' title='"
                     .get_string('invite_tooltip_delete', 'local_treestudyplan')."'";
             print " ><i class='fa fa-trash'></i></a>";
 
@@ -117,7 +117,7 @@ if (!get_config("local_treestudyplan", "enableplansharing")) {
     }
     print "</tbody></table>";
 
-    print "<a class='btn btn-info' href='/local/treestudyplan/edit-invite.php?add=true' class='btn btn-primary' id='add_invite'>";
+    print "<a class='btn btn-info' href='{$CFG->wwwroot}/local/treestudyplan/edit-invite.php?add=true' class='btn btn-primary' id='add_invite'>";
     print "<i class='fa fa-plus'></i> ".get_string('invite_button_new', 'local_treestudyplan')."</a>";
 
     print $OUTPUT->footer();