sample5.aspx

<h2>Assign Instructors to Courses or Remove from Courses</h2>
    <br />
    <asp:EntityDataSource ID="InstructorsEntityDataSource" runat="server" 
        ContextTypeName="ContosoUniversity.DAL.SchoolEntities" EnableFlattening="False" 
        EntitySetName="People"
        Where="it.HireDate is not null" Select="it.LastName + ', ' + it.FirstMidName AS Name, it.PersonID">
    </asp:EntityDataSource>
    Select an Instructor:
    <asp:DropDownList ID="InstructorsDropDownList" runat="server" DataSourceID="InstructorsEntityDataSource"
        AutoPostBack="true" DataTextField="Name" DataValueField="PersonID"
        OnSelectedIndexChanged="InstructorsDropDownList_SelectedIndexChanged" 
        OnDataBound="InstructorsDropDownList_DataBound">
    </asp:DropDownList>
    <h3>
        Assign a Course</h3>
    <br />
    Select a Course:
    <asp:DropDownList ID="UnassignedCoursesDropDownList" runat="server"
        DataTextField="Title" DataValueField="CourseID">
    </asp:DropDownList>
    <br />
    <asp:Button ID="AssignCourseButton" runat="server" Text="Assign" OnClick="AssignCourseButton_Click" />
    <br />
    <asp:Label ID="CourseAssignedLabel" runat="server" Visible="false" Text="Assignment successful"></asp:Label>
    <br />
    <h3>
        Remove a Course</h3>
    <br />
    Select a Course:
    <asp:DropDownList ID="AssignedCoursesDropDownList" runat="server"
        DataTextField="title" DataValueField="courseiD">
    </asp:DropDownList>
    <br />
    <asp:Button ID="RemoveCourseButton" runat="server" Text="Remove" OnClick="RemoveCourseButton_Click" />
    <br />
    <asp:Label ID="CourseRemovedLabel" runat="server" Visible="false" Text="Removal successful"></asp:Label>