Unable to delete records in grid view

Question

Hi, I encountered a problem with deleting records from database. This is the error:

Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

May I know what causes it?
This is the business logic:

 

protected void 
gvUploadedDocuments_RowDeleting(object sender, GridViewDeleteEventArgs e)

{

vrmdb.Delete_UploadedNewDocuments(gvUploadedDocuments.DataKeys[e.RowIndex].Values[0].ToString());

BindGrid1();

}

Thanks!