diff --git a/html/exhi/application/controllers/Company.php b/html/exhi/application/controllers/Company.php
index 9b4bea96a814d14f221c4bf287abd45206ff0bed..568cfb5ac85cefa647659003912b85afa800bbdd 100644
--- a/html/exhi/application/controllers/Company.php
+++ b/html/exhi/application/controllers/Company.php
@@ -19,10 +19,19 @@ class Company extends Exhibition_Controller {
 	}
 
 	public function delete_company(){
+		$data['message'] = true;
 		$id = $this->input->post('id');
 		$this->load->model('company/M_company','company');
-		$this->company->delete_company($id);
-		$data['message'] = true ;
+		$this->load->model('project/M_project','project');
+		$projects = $this->project->get_all()->result();
+		foreach($projects as $project){
+			if($project->company_id == $id){
+				$data['message'] = false;
+			}
+		}
+		if($data['message'] != false){
+			$this->company->delete_company($id);
+		}
         echo json_encode($data);
 	}
 
diff --git a/html/exhi/application/controllers/Instructor.php b/html/exhi/application/controllers/Instructor.php
index 8078f0152ea9e5a068455ee6f03c809d19f08fc3..51b36348ec4316a97a80a3884ed6759614d77bc3 100644
--- a/html/exhi/application/controllers/Instructor.php
+++ b/html/exhi/application/controllers/Instructor.php
@@ -19,10 +19,19 @@ class Instructor extends Exhibition_Controller {
 	}
 
 	public function delete_instructor(){
+		$data['message'] = true ;
 		$id = $this->input->post('id');
 		$this->load->model('instructor/M_instructor','instructor');
-		$this->instructor->delete_instructor($id);
-		$data['message'] = true ;
+		$this->load->model('project/M_project','project');
+		$projects = $this->project->get_all()->result();
+		foreach($projects as $project){
+			if($project->instructor_id == $id){
+				$data['message'] = false;
+			}
+		}
+		if($data['message'] != false){
+			$this->instructor->delete_instructor($id);
+		}
         echo json_encode($data);
 	}
 
diff --git a/html/exhi/application/controllers/Tag.php b/html/exhi/application/controllers/Tag.php
index 4d268e8a79d3b275f71e7cdefcef742d50314f07..91803b403c8f866a241a6253dd6a8d84f5a826c2 100644
--- a/html/exhi/application/controllers/Tag.php
+++ b/html/exhi/application/controllers/Tag.php
@@ -19,10 +19,17 @@ class Tag extends Exhibition_Controller {
 	}
 
 	public function delete_tag(){
+		$data['message'] = true;
 		$id = $this->input->post('id');
 		$this->load->model('tag/M_tag','tag');
-		$this->tag->delete_tag($id);
-		$data['message'] = true ;
+		$this->load->model('project_tag/M_project_tag','project_tag');
+		$project_tag = $this->project_tag->get_project_tag_by_tag_id($id)->result();
+		if(count($project_tag) > 0){
+			$data['message'] = false;
+		}
+		if($data['message'] != false){
+			$this->tag->delete_tag($id);
+		}
         echo json_encode($data);
 	}
 
diff --git a/html/exhi/application/controllers/User.php b/html/exhi/application/controllers/User.php
index d9ee93ae27f165c06f043c98a457bb9ab85a34d7..b6c7a5055fc5ff2ab902a9f150061ddb5ac16495 100644
--- a/html/exhi/application/controllers/User.php
+++ b/html/exhi/application/controllers/User.php
@@ -93,10 +93,26 @@ class User extends Exhibition_Controller {
 
 
 	public function delete_user(){
+		$data['message'] = true ;
 		$id = $this->input->post('id');
 		$this->load->model('user/M_user','user');
-		$this->user->delete_user($id);
-		$data['message'] = true ;
+		$this->load->model('project/M_project','project');
+		$this->load->model('member/M_member','member');
+		$projects = $this->project->get_all()->result();
+		foreach($projects as $project){
+			if($project->user_id == $id){
+				$data['message'] = false;
+			}
+		}
+		$members = $this->member->get_all()->result();
+		foreach($members as $member){
+			if($member->user_id == $id){
+				$data['message'] = false;
+			}
+		}
+		if($data['message'] != false){
+			$this->user->delete_user($id);
+		}
         echo json_encode($data);
 	}
 
diff --git a/html/exhi/application/models/member/M_member.php b/html/exhi/application/models/member/M_member.php
index 8325ac73144ff19d80e354f5d4c0770e42d14115..4a0621875d8373df88a773dc8ed86e97aeca3d05 100644
--- a/html/exhi/application/models/member/M_member.php
+++ b/html/exhi/application/models/member/M_member.php
@@ -11,6 +11,12 @@ class M_member extends Da_member
 		parent::__construct();
 	}
 
+	public function get_all(){
+		$sql = "SELECT * FROM {$this->db_name}.member";
+        $query = $this->db->query($sql);
+        return $query;
+	}
+
 	public function get_member_by_project_id($id){
 		$sql = "SELECT * FROM {$this->db_name}.member
 		Where project_id = $id";
diff --git a/html/exhi/application/models/project_tag/M_project_tag.php b/html/exhi/application/models/project_tag/M_project_tag.php
index 7520edfdb965ec6a149f6eaf219c756d9e2278c3..2403cc40f517ac35bc53ce48afc7ec32ed7703f2 100644
--- a/html/exhi/application/models/project_tag/M_project_tag.php
+++ b/html/exhi/application/models/project_tag/M_project_tag.php
@@ -18,6 +18,13 @@ class M_project_tag extends Da_project_tag
         return $query;
 	}
 
+	public function get_project_tag_by_tag_id($id){
+		$sql = "SELECT * FROM {$this->db_name}.project_tag
+		Where tag_id = $id";
+        $query = $this->db->query($sql);
+        return $query;
+	}
+
 	public function get_by_id($id){
 		$sql = "SELECT * FROM {$this->db_name}.project_tag
 		join tag on project_tag.tag_id = tag.tag_id
diff --git a/html/exhi/application/views/company/v_company_manage.php b/html/exhi/application/views/company/v_company_manage.php
index 823b67c31158db94b55bafb5cf2b3aac7f4389a8..3de14e563d7f08057f9a74fdd2174da1851c40e9 100644
--- a/html/exhi/application/views/company/v_company_manage.php
+++ b/html/exhi/application/views/company/v_company_manage.php
@@ -345,7 +345,7 @@ function delete_company(id) {
                     } 
                     else {
                         Toast.fire({
-                            icon: 'success',
+                            icon: 'error',
                             title: 'ลบข้อมูลไม่สำเร็จ',
                         });
                     } 
diff --git a/html/exhi/application/views/user/v_user_manage.php b/html/exhi/application/views/user/v_user_manage.php
index 158dff3a1af1b1829734c3d724dbc81e1f322c98..ef1edece100bce2cf9e80dd19093d569446e7b00 100644
--- a/html/exhi/application/views/user/v_user_manage.php
+++ b/html/exhi/application/views/user/v_user_manage.php
@@ -161,7 +161,7 @@ function delete_user(id) {
                     } 
                     else {
                         Toast.fire({
-                            icon: 'success',
+                            icon: 'error',
                             title: 'ลบข้อมูลไม่สำเร็จ',
                         });
                     }