Counting With Buttons
1. Input Field
Basic Help
More of this Feature
Here is a rather interesting form field that we can construct using Javascript. This input field is not intended to be entered directly, instead the value in the field is updated by selecting the buttons on either side of the field as many times as is required to update the field to the required value. Here is an example:
This effect is fairly easily achieved. All that you need to do is to copy the following simple Javascript code into the head section of your page and then access the functions from within the form.
function add() {cnt++;set();}
function sub() {cnt--;set();}
function set() {myform.count.value = cnt;}
You can of course modify the code within the add() and sub() functions if you require that the field value be kept between specific boundary values.
The actual coding of the form to achieve this effect is as follows. Note that the onblur processing sets the value of the field back to whatever value was in the field before so as to effectively prevent the field from being updated directly.
<input type="button" value="-"
onclick="sub()" /><input type="input"
value="0" size="3" name="count"
onblur="set();" /><input type="button"
value=" + " onclick="add()" />
</form>
With a little more work we can do away with the input field and directly update the plain text between the buttons.
