I am designing a job rota planner for a company and need help displaying a dynamic table containing the staff details. I have the following tables in MySQL database: Staff, Event, and Job. The staff table holds staff details (staffed, name, address...etc), the Event table (eventide, eventName, Fromdate, Todate...etc) and the Job table holds (Jobid, Jobdate, Eventid(fk), Staffid (fk)). I need to dynamically display the available staff list from the staff table when the user selects the EVENT and the DATE (3 drop downs: date, month, and year) from a PHP form. I need to display staff members that have not been assigned work on the selected date by checking the Jobdate in the Job table. I have been at this for all day and can't get around it. I am still learning PHP and would surely appreciate any help I can get. My current code displays all staff members when an event is selected:

 if(isset($_POST['submit'])) 
 { 
$eventId = $_POST['eventradio'];

 }
 $timePeriod = $_POST['timeperiod'];
 $Day = $_POST['day'];
 $Month = $_POST['month'];      
 $Year = $_POST['year'];
 $dateValue = $Year."-".$Month."-".$Day;
 $selectedDate = date("Y-m-d", strtotime($dateValue));

//construct the available staff list
if ($selectedDate)
    {
        $staffsql = "SELECT s.StaffId, s.LastName, s.FirstName
        FROM Staff s 
        WHERE s.StaffId NOT IN
        (SELECT J.StaffId
        FROM Job J
        WHERE J.JobDate != ".$selectedDate.")";
        $staffResult = mysql_query($staffsql) or die (mysql_error());

    }
if ($staffResult){
    echo "<p><table cellspacing='1' cellpadding='3'>";
    echo "<th colspan=6>List of Available Staff</th>";
    echo "</tr><tr><th> Select</th><th>Id</th><th></th><th>Last Name
        </th><th></th><th>First Name </th></tr>";

    while ($staffarray = mysql_fetch_array($staffResult))
    {
        echo "<tr onMouseOver= this.bgColor = 'red' onMouseOut =this.bgColor = 'white' bgcolor= 
            '#FFFFFF'> <td align=center><input type='checkbox' name='selectbox[]'
            id='selectbox[]' value=".$staffarray['StaffId'].">
            </td><td align=left>".$staffarray['StaffId']."
            </td><td>&nbsp&nbsp</td><td align=center>".$staffarray['LastName']."
            </td><td>&nbsp&nbsp</td><td align=center>".$staffarray['FirstName']."
            </td></tr>";
    }
        echo "</table>";
    }
    else {
        echo "<br> The Staff list can not be displayed!";
    }       
    echo "</td></tr>";
    echo "<tr><td></td>";
    echo "<td align=center><input type='submit' name='Submit' value='Assign Staff'>&nbsp&nbsp";
    echo "<input type='reset' value='Start Over'>";
    echo "</td></tr>";
    echo "</table>";