I've got an Excel worksheet with the following VB code

Sub Button1_Click()
ThisWorkbook.SendMail ", _
"Timesheet"

MsgBox "Thank you, Your timesheet has been sent",
0, "Item Sent"

End Sub

When I click the submit button I get the following error

Run-time error '1004':
Method 'SendMail' of object '_Workbook' failed

I've looked on the MS Knowledge Base, and tried the
example code in Article 241421, and that came back
saying 'no mail client'.

I am running WinXP, Excel 2002, and Outlook 2002, if in
Excel I do file-send to it succesfully opens outlook, so
it must be seeing it as my default mail client.

Can anyone help with this, and give me some pointers?