listbox validation by javascript

[sonysunny]

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

[hsriat]

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

var selectedOptions = new Array(); //array containing the ids of selected options
function doSelect(whom) {
    var temp;
    if (selectedOptions.length == 3) { //required length
        temp =  selectedOptions.shift();
        document.getElementById(temp).selected = false;
    }
    temp = selectedOptions.push(whom.id);
}
 

On the onclick of every option, call the function doSelect(this).
* And don't forget to set autocomplete=of f 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?