Changed behavior of OpenSheet functions

In PowerBuilder 8 and later, the OpenSheet and OpenSheetWithParm functions might throw a runtime error on failure instead of returning -1. For example, this occurs when the optional windowtype argument is invalid. To ensure that this error is trapped, wrap the call in a try-catch statement in addition to checking the return value:

integer li_ret 
try li_ret = OpenSheet(w_child, "w_child_1", MDI_User, 2, Original!) 
 if li_ret <> 1 then 
 MessageBox("OpenSheet failed", "Check arguments") 
catch (RuntimeError rt) 
 MessageBox("OpenSheet failed", rt.GetMessage() ) 
// Handle error end try