web2plc in TIA Portal V11

Hello all,

I am using Siemens TIA portal V11 for 1211c CPU and encountering an error during the web2plc. The WWW instruction gives an error at the output (RET_VAL). Even after defining the RET_VAL tag, it says that the tag is not defined. Since this is my first time dealing with this PLC therefore I do not have enough knowledge about it.

Kindly help me with matter ASAP.

Here is a link to a sample app using web pages with the S7-1200:
http://support.automation.siemens.com/WW/view/en/58862931