PlaySound('ONLINE2', HInstance, SND_RESOURCE);
In your project1.lpi file, your "ONLINE2" resource is set to a resource type of "RCDATA":
<Resource_0 FileName="audio\online2.wav" Type="RCDATA" ResourceName="ONLINE2"/>
It needs to be set to a resource type of "WAVE" instead, or else PlaySound() will not be able to find it at runtime.
Otherwise, you can manually obtain a memory pointer to the resource data using FindResource()/LoadResource()/LockResource(), and then use SND_MEMORY instead of SND_RESOURCE to play it.