Error with Crystal Report. Reply early as possible?

Question

Error14The type 'CrystalDecisions.CrystalReports.Engine.ReportDocument' exists in both 'c:\WINDOWS\assembly\GAC_MSIL\CrystalDecisions.CrystalReports.Engine\10.5.3700.0__692fbea5521e1304\CrystalDecisions.CrystalReports.Engine.dll' and 'c:\WINDOWS\assembly\GAC_MSIL\CrystalDecisions.CrystalReports.Engine\10.2.3600.0__692fbea5521e1304\CrystalDecisions.CrystalReports.Engine.dll'D:\Projects\PTS\Intranet_PTS\UI\UserReport.aspx.cs1912D:\...\Intranet_PTS\


I'm using crystal report i'm use both CrystalDecisions.CrystalReports.Engine and    CrystalDecisions.Reportsource namespaces, thanks in advance