Assume you have two Edit controls named EDIT1 & EDIT2 and a Check Box named ChkBoxSkip.
OnClick on ChkBoxSkip, you may want to set null value or empty string to EDIT1 & EDIT2 and disable them. Technically you should be able to define SetProperty CustomActions and add them under ChkBoxSkip events. But due to current limitation in InstallShield, it does not work this way.
Create two additional Edit controls named EDIT1_1 & EDIT2_2 and disable them by default. The default value of ChkBoxSkip should be set to 1 and there is no need to create IS_SKIP_CHECKED property in the Property Manager.
The properties associated to these controls are defined in below table
Now you will have to display EDIT1 & EDIT2 controls when ChkBoxSkip is UNCHECKED and display EDIT1_1 & EDIT2_2 when ChkBoxSkip is CHECKED. To achieve this, set the following contions for each of the Edit Controls.
Control Property EDIT1 USERNAME EDIT2 EMAILID EDIT1_1 DUMMY EDIT2_2 DUMMY ChkBoxSkip IS_SKIP_CHECKED
Control Action Condition EDIT1 Hide SKIP_CHECKED Show Not SKIP_CHECKED Enable Not SKIP_CHECKED EDIT2 Hide SKIP_CHECKED Show Not SKIP_CHECKED Enable Not SKIP_CHECKED EDIT1_1 Hide Not SKIP_CHECKED Show SKIP_CHECKED EDIT2_2 Hide Not SKIP_CHECKED Show SKIP_CHECKED
with this, from the user's perspective EDIT1 & EDIT2 will be enabled with ChkBoxSkip is UNCHECKED and disabled & cleared when ChkBoxSkip is CHECKED. But actually the Property associated with EDIT1 and EDIT2 can be reset by using SetProperty CA OnClick on Next button.
Note: Applies to Basic MSI Project and verified in InstallShield 2012.