somebody pls help me...
i'm very new in php...i have a problem when search database using multiple dropdownlist...
i call so many function like below to search
....either user select one dropdown list..
either two dropdownlist and all selected...
how can i combine all together in one function?call one function only whatever selection that user made..

some part in html:

<select name="Location" id="Location">
......
</select>

<select name="Subject" id="Subject">
.......
</select>

<select name="Semester" id="Semester">
...........
</select>


some part in php...

if (isset($_POST['submit'])) {

if ($_POST['Location'] && $_POST['Subject'] && $_POST['Semester'] ){

.....
$staff=$staff->getLecturers_Loc_Sub_Sem($_POST['Location'],$_POST['Subject'],$_POST['Semester']);}

else if ($_POST['Location'] && $_POST['Subject']){

.......
$staff=$staff->getLecturers_Loc_Sub($_POST['Location'],$_POST['Subject']); }

else if ($_POST['Location'] && $_POST['Semester']){

...........
$staff=$staff->getLecturers_Loc_Sem($_POST['Location'],$_POST['Semester']); }

else if ($_POST['Subject'] && $_POST['Semester']){

.......
$staff=$staff->getLecturers_Sub_Sem($_POST['Subject'],$_POST['Semester']); }

else if ($_POST['Location']){

.............
$staff=$staff->getLecturers_Loc($_POST['Location']); }

else if ($_POST['Subject']){

..............
$staff=$staff->getLecturers_Sub($_POST['Subject']); }

else if ($_POST['Semester']){

...........
$staff=$staff->getLecturers_Sem($_POST['Semester']); }

some sql statement when search location and subject in this function...

getLecturers_Loc_Sub($id1,$id2); {
....
$sql= "select * from intake i,intake_subject ij, staff_subject ss
where i.location=$id and ss.subject=$id2
and i.id=ij.intake and ij.subject=ss.subject group by ss.staff";
.....
}

Can't you give them default values?

function getLecturers($id1=0,$id2=0,$id3=0)
{...
} 

if(isset($_POST['submit']))
{/*$staff=*/$staff->getLecturers($_POST['Location'],$_POST['Subject'],$_POST['Semester']);
}

and I dunno why you must return something to the Class.

: Can't you give them default values?

function getLecturers($id1=0,$id2=0,$id3=0)
: {...
: } 
: 
: if(isset($_POST['submit']))
: {/*$staff=*/$staff->getLecturers($_POST['Location'],$_POST['Subject'],$_POST['Semester']);
: }

and I dunno why you must return something to the Class.
:

I solve those problems like this:

function getLecture($loc, $subject, $sem)
{
// I don't know your table structure so I call my fileds Location, Subject and Semester
   $sql = 'SELECT * FROM my_list WHERE 1';
   if ($loc) $sql .= ' AND Location="'.$loc.'"';
   if ($subject) $sql .= ' AND Subject="'.$subject.'"';
   if ($sem) $sql .= ' AND Semester="'.$sem.'"';

   // you should always produce nice SQL
   $sql .= ';';

   $resul = mysql_query($sql); // or whatever API you use
}