Dropdown menu php with next/previous button - php

Question

I have :
<select name="department" id="department" onchange="this.form.submit()">
<?php
do {
?>
<option value="<?php echo $row_department['dept_Name'] ?>"><?php echo $row_department['dept_Name'] == $department ? 'selected' : ''?><?php echo $row_department['dept_Name']
?></option>
<?php
} while ($row_department = mysql_fetch_assoc($department));
$rows = mysql_num_rows($department);
if($rows > 0) {
mysql_data_seek($department, 0);
$row_department = mysql_fetch_assoc($department);
}
?>
</select>
For the dropdown from the database named department.
Once dropdown selected, multiple file sets will viewed from database such as id, name, dept_name with next/previous button.
The problem is, whenever i clicked next/previous button, there no files viewed.
Dropdown must be selected for the 2nd time for view 2nd file set.
What should I do and how? I'm using Dreamweaver CS6.

Answer 1

Try this. You canno't search because you don't have a query to do that.
$deptName = $row['dept_Name'];
$sql = mysql_query("SELECT * FROM (table_name) WHERE (column_department_name) = '$deptName'");
while ($row_department = mysql_fetch_assoc($sql));
$rows = mysql_num_rows($row_department);
if($rows > 0) {
echo $rows['(your_column_name)'];
}else{
echo 'nothing';
}