从具有MySQL数据的列表框中获取选择的选择值，以打开另一个列表框并使用此值获取mysql数据

Question

Im starting in javascript so, I need to do this : From a list box(already has mysql data using php) I want to get the current selection id (select,selected I think in Java) and fill a listbox with data using the id of the first listbox.But this must happens on onChange property of the listbox1 but on selection. Here is what I have so far Html code Select a Region

$result_disp = mysql_query($query_disp, $cn);
$res=mysql_select_db("xxxx",$cn) or die("Note: " . mysql_error());

$res=mysql_query("select Region_ID, Region_Description from regions");
while($query_data = mysql_fetch_array($res))
{
?>

<option value="<? echo $query_data["Region_ID"]; ?>"
<?php if ($query_data["Region_ID"]==$_post['Region_ID']) ?>>
<? echo $query_data["Region_Description"]; ?></option>
<? } ?>
<select name="Dep" id="Items">
<option>Département</option>
</select>

javascript

function setSelect(id,value) {
var sel = document.getElementById(id);
var option, options = sel.options;
var i = options.length;
while (i--) {
option = options[i];
option.selected = (option.value == value)? true : false;

}
}

thanks in advance!

Answer 1

If you want to manipulate and query the DOM, use the great javascript library jQuery .

Once you have jQuery downloaded and included in your page, you can then do things like this:

<select id='myFirstSelect'>
    <option value="1"/>
    <option value="2"/>
</select>

javascript: (Bind a function to the 'changed'-event)

$('#myFirstSelect').changed(function(){
    var selectedValue = $(this).val();
    //do something with selectedValue, e.g. $('#someOtherSelect').val(selectedValue);
});

I haven't tested this code, it's just to give you an idea how much faster and more elegant you get ahead, once you get into jQuery (keywords: Selectors and Events)