Identifying the DialogBox in firefor

[MahalakshmiDevi]

I am automating userlogin.I would record the script in IE and run the same code in FireFox.On clicking on "Login" button on leaving the user name empty the dialog "Enter username" would appear.In I.E the dialog is recognized where as in firefox the dialog is not recognized.

I have written the following code but error is getting displayed

Code:

str=Browese("").GetROproperty("application version")
If not (strcomp(str,"Internet Explaorer 6")) Then
  Browser("micClass:=Browser")Page("micClass:=page").Dialog("micClass:=Dialog").Click()
End IF