public void GetAllDepartment()
{
DepartmentDropDownList.DataSource = _CourseAssigneManager.GetAllDepartment();
DepartmentDropDownList.DataTextField = "DeptName";
DepartmentDropDownList.DataValueField = "Id";
DepartmentDropDownList.DataBind();
DepartmentDropDownList.Items.Insert(0, new ListItem("Select Department", "0"));
Courses _Course = new Courses();
_Course.DepartmentId = Convert.ToInt32(DepartmentDropDownList.SelectedValue);
}