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listbox validation by javascript

hai,

How can i restrict number of selections in listbox using javascript.
ie. only 3 items are allowed to select , also atleast one item should select.

thanks in advance
Feb 23 '08 #1
1 1944
hsriat
1,654 Expert 1GB
hai,

How can i restrict number of selections in listbox using javascript.
ie. only 3 items are allowed to select , also atleast one item should select.

thanks in advance
Expand|Select|Wrap|Line Numbers
  1. var selectedOptions = new Array(); //array containing the ids of selected options
  2. function doSelect(whom) {
  3.     var temp;
  4.     if (selectedOptions.length == 3) { //required length
  5.         temp =  selectedOptions.shift();
  6.         document.getElementById(temp).selected = false;
  7.     }
  8.     temp = selectedOptions.push(whom.id);
  9. }
  10.  
On the onclick of every option, call the function doSelect(this).
* And don't forget to set autocomplete=off to the select input.

Check if this works or not. I didn't check it.

PS: Are you sure there's not any HTML attribute to restrict it?
Feb 23 '08 #2

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