VB.Net 2008 - Can't get SelectionFormula to work on CrystalReportviewer

[Markei54545]

This works..

CrystalReportViewer1.SelectionFormula = {invoices.invno} = 23087

This doesn't (even though the invoices exist)

CrystalReportViewer1.SelectionFormula = {invoices.invno} = 23087 OR
{invoices.invno} = 23088 OR {invoices.invno} = 23089

What I am trying to do is pass a list of invoices to the report to
print.

Hope that makes sense. Anybody know why?

Cheers