Video URL is now checked for validity

lib/logic.lib

@@ -41,12 +41,29 @@ gui()
 {
   VIDURL=$(${SET_GUI_BIN} --title="Zymp3 0.1-6" --height=${URL_BOX_HEIGHT} --width=${URL_BOX_WIDTH} --entry  --text "Paste youtube link here: ")
 
-  if [[ $? == 0 ]] ; then
-  gui2
+
+  if [[ ${VIDURL} == *"https://www.youtube.com"* ]];then
+    echo "valid URL"
+    if [[ $? == 0 ]] ; then
+      gui2
+
+    else
+      exit 0;
+    fi
   else
-     exit 0;
+    echo "This is not a valid URL, please double check it."
+    ${SET_GUI_BIN} --error --text "This is not a valid URL, please double check it."
+    if [[ $? == 0 ]] ; then
+      gui
+
+    else
+      exit 0;
+    fi
   fi
 
+  
+  
+