Merge branch 'master' of http://s.dev01.dkiboss.com:9001/DK-MES-2.0/IMEX.mes.wcf

DK.Client/SystemModule/F_MST_0502.cs

@@ -710,7 +710,7 @@ namespace Dongke.IBOSS.PRD.Client.SystemModule
 		private int ValidationText()
 		{
 			int ErrorID = 0;
-			if (this.ddlGlazeTypeID.SelectedValue.ToString() == string.Empty)
+			if (this.ddlGlazeTypeID.SelectedValue ==  null)
 			{
 				ErrorID = 7;
 			}