problem with calculation

[theo1985]

i have these 2 selections

    <select id="rooms" name="rooms">
  <option>Please Choose</option>
  <option value="1" >1</option>
  <option value="2" >2</option>
  <option value="3" >3</option>
  <option value="4" >4</option>
   </select>

      <select id="type" name="type">

  <option>Please Choose</option>
  <option>Single - 50£</option>
  <option>Double - 60£</option>
  <option>Luxury double - 70£</option>
  </select>

i would like to give these values
single:50
double:60
luxury double:70
1)how can i do that?
2)if i choose for example single room and number of rooms 2 how can i have the result 100?

Thank you

[BIOSTALL]

Maybe something like so will work:

<script type="text/javascript">
  function calculate_total() {

    var no_rooms = document.getElementById('rooms').value;
    var room_type = document.getElementById('type').value;
    var total = 0;

    if (no_rooms!="" && room_type!="") { // if both dropdowns contain values
      total = parseInt(no_rooms) * parseInt(room_type);
    }

    document.getElementById('current_total').innerHTML = total;

  }
</script>

Number of Rooms:
<select id="rooms" name="rooms" onchange="calculate_total()">
  <option value="">Please Choose</option>
  <option value="1" >1</option>
  <option value="2" >2</option>
  <option value="3" >3</option>
  <option value="4" >4</option>
</select>
<br />
Room Type:
<select id="type" name="type" onchange="calculate_total()">
  <option value="">Please Choose</option>
  <option value="50">Single - 50&#163;</option>
  <option value="60">Double - 60&#163;</option>
  <option value="70">Luxury double - 70&#163;</option>
</select>

Current Total: <span id="current_total"></span>

I haven't tested that but hopefully it gets you started. Notice how on the change of each dropdown we calculate the total by multiplying the two dropdown values together.

[theo1985]

thank you very much for your help.This works nice...I would like to ask you something else..
i create a new selection with the number of people.
I want to do this:
If a single person books a double room a single-occupancy supplement should be charged. For example
Double room with shower and WC:
If 2 people sharing, price per person per night, £60.
If 1 person only - £90 per night.

<script type="text/javascript">
  function calculate_total() {
    
    var no_people = document.getElementById('people').value;
    var no_rooms = document.getElementById('rooms').value;
    var room_type = document.getElementById('type').value;
    var total = 0;

    if (no_rooms!="" && room_type!="" && breakf!="" && no_people!="1" ) 
{ // if both dropdowns contain values
      total = parseInt(no_rooms) * parseInt(room_type) + parseInt(breakf);
    }
else
{
     total = parseInt(no_rooms) * parseInt(room_type) + parseInt(breakf)+10;
}
    document.getElementById('current_total').innerHTML = total;

  }
</script>

 Number of people
 <br>
         <select id="people" name="people" >
    <option value="">Please Choose</option>
    <option value="1" >1</option>
    <option value="2" >2</option>
    <option value="3" >3</option>
    <option value="4" >4</option>
    </select>

         </br>

Number of Rooms:
<select id="rooms" name="rooms" onchange="calculate_total()">
  <option value="">Please Choose</option>
  <option value="1" >1</option>
  <option value="2" >2</option>
  <option value="3" >3</option>
  <option value="4" >4</option>
</select>
<br />
Room Type:
<select id="type" name="type" onchange="calculate_total()">
  <option value="">Please Choose</option>
  <option value="50">Single - 50&#163;</option>
  <option value="60">Double - 60&#163;</option>
  <option value="70">Luxury double - 70&#163;</option>
</select>

Current Total: <span id="current_total"></span>

The result does not change!!!Somewhere in IF i think that is my fault.Could you please help me?