unable to get Form Object when uploading file

[ajith kumar]

Iam trying to upload an excel sheet to the server and read the values and store them in the database . Iam using the struts tag

<html:thefile>
Iam able to upload the excel sheet with less number of rows (around 10) but once number of rows increases the
set method in the file is not getting called .

In the action when iam trying to create an object for the form in the Action iam geting a null for the file object .
UploadForm theForm = (UploadForm) form;
FormFile file = theForm.getTheFile();


the set method is as follows
public void setTheFile(FormFile theFile)
{

this.theFile = theFile;
}

Why the set method is not getting called??

Could any body please comment on this issue???