fixed check

WindStressPRM/Objects/PowerStation.cs

@@ -87,15 +87,15 @@ namespace WindStressPRM
             this.IsON = false;
             CheckValue();
         }
-        public void CheckValue()
+        public bool CheckValue()
         {
-            bool checker = Identifier >= 0;
             if (Identifier < 0) {
                 throw new System.ArgumentOutOfRangeException("Identifier", Identifier, "Identifer expected to be more than 0"); 
             }
             if (Voltage < 0 || Voltage > 1500) {
                 throw new System.ArgumentOutOfRangeException("Voltage", Voltage, "Voltage expected to be in range (0,1500)"); 
             }
+            return true;
         }
         /// <summary>
         /// Gets attached lines list