correcting a id checking

pages/provide_sentences_mongo.py

@@ -142,7 +142,7 @@ def delete_line():
     
     number = st.session_state.line1
     
-    if not number in sentences['_id']:
+    if not number in set(sentences['_id']):
         
         st.warning("The line that you provided does not exist !")
     
@@ -160,7 +160,7 @@ def modify_line():
     
     number = st.session_state.line2
     
-    if not number in sentences['_id']:
+    if not number in set(sentences['_id']):
         
         st.warning("The line that you provided does not exist !")