Dim a = 7

a = 0/0

<configuration>
<system.webServer>
    <httpErrors errorMode="Detailed" />
</system.webServer>
<system.web>
    <customErrors mode="Off"/>
    <compilation debug="true"/>
</system.web>

IF Err.Number <> 0 THEN
    Response.Write "=========================================" & "<br />"
    Response.Write "Error description: " & Err.Description     & "<br />"
    Response.Write "Source: " & Err.Source                     & "<br />"
    Response.Write "LineNumber: " & Err.Line                   & "<br />"
    Response.Write "=========================================" & "<br />"
END IF