http://stackoverflow.com/questions/12370472/file-upload-validation-in-xpages

Thanks for Reply !!

I can use below code but not a formula bcoz i have multiple attachment field (RTs)

if( document1.getAttachmentList("Body").isEmpty() ){
    var msg = new javax.faces.application.FacesMessage("No File added!");
    facesContext.addMessage( "No File!", msg );
    return false;
}

But the above code didn't work. Do i need to design a facet to work or Error message control is okay. Please tell me the process

It must be used together with the Error Messages control (the one that can show errors from multiple different controls).

And also from the link that I suggested, you cannot seem to use a "Submit" button. You have to use just a normal button to do the document save. In your case, just put document1.save() after the if statement.