Javascript for searching in list box

[nitin pai]

Hi,

I wanted to have a real time search facility for the items in a list box i.e As the user keeps typing in character the matching item would get selected. The code below worked fine when I had set multiple=false in the list box. But due to new requirements I had to change it to multiple=multiple. After the change the below code acts weird, even though I have included a small change in the script, to deselect the earlier selected item.
Please help.

//Method to interactively search the left select box items
	var previousSelectedIndex;
	function searchItem(keyword){											
		var itemList = document.getElementById("selectCol");	
		var searchBox = document.getElementById("searchBox");	
		if(previousSelectedIndex){
			itemList.options[previousSelectedIndex].selected = false;
			alert("clear");
		}
		//alert(keyword);
		for (var i=0;i<itemList.options.length ;i++ ){												
			 if(checkIfExists(itemList.options[i].text, keyword)){									
				  itemList.options[i].selected = true;  
				  previousSelectedIndex = i;
				  itemList.focus(); 
				  searchBox.focus();
				  //alert();
				  break;
			 }
		}
	}//end searchItem

       //utility method to check the select box item with the entered real time characters
	function checkIfExists(text, keyword){
		var len = keyword.length;
		var substr = text.substring(0,len);											
		if(substr.toLowerCase() == keyword.toLowerCase())
			return true;
		return false;
	}//end checkIfExists

><input type=text id="searchBox" style="width: 300px" value="Enter the name to search" onkeyup="searchItem(this.value)" onmouseup="this.value=''">
  <select name="selectCol" id="selectCol" size="20" multiple="multiple">

[David Newton]

"The code acts weird?" And we're supposed to figure out what "weird" means in this context... how?

[nitin pai]

apologies for not mentioning the behavior which I am getting..

What is happening now is that sometimes the selected option remains selected and the searched item also gets selected, so the user gets to see that two items in the list are selected and this, is not the expected behavior. I want that whatever the user types, should select only one entry or rather the first entry which matches exactly with the characters he has typed in.....

[David Newton]

Well, it'll never get cleared if the first item in the list is selected. Other than that, try debugging it.