3 replies to this topic

[system32]

I have a forum where I want to do a simple calculation in JavaScript and when I click a button, a textbox value is entered from my function. How can I do this? My code does not seem to work.

        function calculate()        {
            var odometerStart = document.getElementById('odometerStart').value;
            var odometerEnd = document.getElementById('odometerEnd').value;
            var distance = document.getElementById('distance');
            
            if (distance)
            {
                distance.value = odometerEnd - odometerStart;
            }            
        }

Odometer: Start <input type="number" name="odometer[Start]" id="odometerStart" min="0" max="999999" placeholder="0" class="required"/><br/>
Odometer: End <input type="number" name="odometer[End]" id="odometerEnd" min="0" max="999999" placeholder="999999" class="required"/><br/>
Distance <input type="text" name="distance" placeholder="0.00"/><br/>
<input type="button" name="calculate" value="Calculate" onclick="calculate()"/>

[RhetoricalRuvim]

Quote

        function calculate()        {

            var odometerStart = document.getElementById('odometerStart').value;

            var odometerEnd = document.getElementById('odometerEnd').value;

            var distance = document.getElementById('distance');

            

            if (distance)

            {

                distance.value = odometerEnd - odometerStart;

            }            

        }

Does this work?:

        function calculate()        {

            var odometerStart = [COLOR=#FF0000]parseFloat ([/COLOR]document.getElementById('odometerStart').value[COLOR=#FF0000])[/COLOR];

            var odometerEnd = [COLOR=#FF0000]parseFloat ([/COLOR]document.getElementById('odometerEnd').value[COLOR=#FF0000])[/COLOR];

            var distance = document.getElementById('distance');

            

            if (distance)

            {

                distance.value = odometerEnd - odometerStart;

            }            

        }

[system32]

Unfortunately no. :(

[lespauled]

The problem is that the distance textbox is null because it doesn't have an id.

The fix:

Distance <input type="text" name="distance" id="distance" placeholder="0.00"/><br/>