selectedIndex value of the last selected item in select box

[samvb]

I need to know how to get id of the last selected item in a multiple list box using javascript. It keeps on givin me 0 or 1...any tips would be great. Note i wanna store it in a variable and that variable should store id of the last selected item.

[philipwayne]

I haven't done much with forms in JavaScript but I'd imagine you could do this with something like

var x = selected.item( selected.length - 1 ).id

[RamananKalirajan]

@samvb,
Can you please share the code what you have done?

Thanks and Regards
Ramanan Kalirajan

[samvb]

function SelectedItems(selectBoxName,maxallowed) {
	//used to know how many items selected in <select box>
	
	var obj=document.getElementById(selectBoxName);
    var lastclicked=obj.selectedIndex;
	
	var btnobj=document.getElementById(submitbutton);//submit or upload or so button.
  var numberSelected=0

  for (var i=0; i < obj.options.length; i++) {
     if (obj.options[i].selected == true){
       numberSelected++;
	 }//end if
        }//end loop


 if (numberSelected>maxallowed){
	 alert("You can't select " + maxallowed + " items. Please deselect at least one item to proceed.");
	 btnobj.disabled=true;

	 obj.options[lastIndex].selected=false;
 return;
 }//end if
 else{
	
 }//end else
}//end function

Now i wanted to store id of the last clicked item in lastindex variable.

[RamananKalirajan]

Hi samvb,
I was not able to understand you requirement clearly. I just gone through your code. From that I can understand that you are having a multiple select element. You can select so many options. Whether you want to find which option was selected finally?

Thanks and Regards
Ramanan Kalirajan

[samvb]

@RamananKaliraj an

When the user selects, say 3 which is the maximum allowed, i need to warn him about it and deselect the last item selected.

[philipwayne]

I misunderstood your post.

<script type="text/javascript">
	var lastIndex = false;
	function validate( select )
	{
		var max = 3;
		var x;
		var count = 0;
		for( x = 0; x < select.options.length; x++ )
		{
			if( select.options[x].selected == true )
				count++;
		}
		if( count > max )
		{
			alert( "To many items selected!" );
			select.options[lastIndex].selected = false;
		}
	}
</script>
<select id="myselect" onchange="validate( this );" multiple="multiple">
	<option onmousedown="lastIndex = this.index">1</option>
	<option onmousedown="lastIndex = this.index">2</option>
	<option onmousedown="lastIndex = this.index">3</option>
	<option onmousedown="lastIndex = this.index">4</option>
	<option onmousedown="lastIndex = this.index">5</option>
	<option onmousedown="lastIndex = this.index">6</option>
	<option onmousedown="lastIndex = this.index">7</option>
</select>

Also do note we must use the onmousedown function not onclick or onmouseup onchange will happen before onclick and onmouseup in term making the function deslected the wrong option.