errorprovider.dipose doesnt fire in c#
===

hello I am making this program in c# and I dont know why errorprovider1.dispose here in my example doesnt work when it is called the second time. i.e(if a textbox is empty the errorprovider will show but after I filled the textbox and pressed the submit button again. it wont go!). I have a form with many textboxes and Im just checking if the fields are empty or not after clicking the submit button. here is my code:



            foreach (Control c in this.college.Controls)
            {

                if (c is TextBox)
                {

                    TextBox textBox = c as TextBox;

                  
                    if (textBox.Text.Equals(string.Empty))
                    {

                     if (string.IsNullOrWhiteSpace(textBox.Text))
                        {
                           
                           
                            errorProvider1.SetError(textBox, "Field Empty");
                            
                        }
                        else
                        {
                            
                            errorProvider1.Dispose();
                    

                        }

                    }
                }
            }




