tool validation not working as the way I want

Discussion created by maxh718 on Sep 16, 2010
Latest reply on Sep 16, 2010 by dhoneycutt-esristaff
I have a python tool which has one "Input Feature Class" and the other is "Output Feature Class",
what I want the tool validation do is when I select the input feature, it will create a output feature class in the same folder using the unique name.

the problem is when I select the input feature class, the output feature class is automatically generated under the scratch folder, doesn't go in the IF condition block.
but when I select the output feature class, no matter what I select, it generate a unique name under the same folder where the input feature class resides, which is what I want, but should be when I select the input feature class

see the tool validation code and the tool parameters