Question

Hey Guys,

Today I am developing a JavaScript quote system,

the JS is as follows

 <script type="text/javascript">
 <!-- Hide this code from non-JavaScript browsers
 function TotalIt() {
 CostPerStairs=25;
 CostPerHall=50;
 CostPerSingle=35;
 CostPerDouble=50;

 f1=document.forms[0]; // abbreviation

 RI=f1.SelR.selectedIndex;
 RV=RI*CostPerStairs;
 HI=f1.SelH.selectedIndex;
 HV=HI*CostPerHall;
 SI=f1.SelS.selectedIndex;
 SV=SI*CostPerSingle;
 CI=f1.SelC.selectedIndex;
 CV=CI*CostPerDouble;
 TV=RV*1+HV*1+SV*1+CV*1;

 RV=Math.round(RV*100)/100;
 HV=Math.round(RV*100)/100;
 SV=Math.round(SV*100)/100;
 CV=Math.round(CV*100)/100;
 TV=Math.round(TV*100)/100;

 f1.TotR.value=RV;
 f1.TotR.value=HV;
 f1.TotS.value=SV;
 f1.TotC.value=CV;
 f1.Total.value=TV;

 return true;
 }
 // End hiding -->
 </script>

The HTML aspect lies here

 

Room Type
Quantity to Clean

Stairs

– 0 –
1
2
3
4

Hall

– 0 –
1
2
3
4

Single Bedroom

– 0 –
1
2
3

Master Bedroom

– 0 –
1
2
3
4
5

 

Total

So – I hear you say – what is the Question?

Essentially, what I would like to add is a poscode drop down box, that initiates a minimum value for the total price TV=RV*1+HV*1+SV*1+CV*1;

The idea is that when a postcode is selected, the value of TV (total) must be a minimum price or above

The HTML I have put in for this is as follows;

<tr>
  <td>Select a Postcode</td>
  <td align="center"><select name="SelP">
    <option>- 0 -</option>
    <option>LS1</option>
    <option>LS2</option>
    <option>LS3</option>
    <option>LS4</option>
  </select>
    <input type="hidden" name="TotR" onFocus="this.blur();" />
    <br></td>
</tr>

However I don’t know how to put this into the Java, I have tried a few ways (basically trial and error), I think i could do it with PHP by using some if and where clauses however I’ve been stumped by the JavaScript here.

Any suggestions would be greatly appreciated.

Answer 1

You want Math.max(x, y). It takes two values and returns the largest of the two, thus setting a minimum value.

var myMinimumValue = f1.SelP.selectedIndex;

// Sets TV to a minimum of selected index of SelP
TV = Math.max(myMinimumValue, TV);

If SelP contains options with specific values (which I guess is what you’re really after) like so:

  <select name="SelP">
    <option value="0">- 0 -</option>
    <option value="200">LS1</option>
    <option value="400">LS2</option>
    <option value="1000">LS3</option>
    <option value="2000">LS4</option>
  </select>

Then you want something like:

var myMinimumValue = f1.SelP[f1.SelP.selectedIndex].value;

// Sets TV to a minimum of the selected value of SelP
TV = Math.max(myMinimumValue, TV);