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Auto Select from Dropdown

Submitted on: 1/6/2015 3:46:00 PM
By: Jason A Buck (from psc cd)  
Level: Advanced
User Rating: By 4 Users
Compatibility: ASP (Active Server Pages), HTML, VbScript (browser/client side)
Views: 956
     Allows you to select an item from a DROP DOWN by typing in more than just the first letter.
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' for :Auto Select from Dropdown
Not done by me, done by Mike Pope, no contact information available
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' Name: Auto Select from Dropdown
' Description:Allows you to select an item from a DROP DOWN by typing in more than just the first letter.
' By: Jason A Buck (from psc cd)
' Returns:A drop down list with the item you typed selected if it is in the list.

				<SCRIPT language=javascript>
				// thanks to GOOD OLE MICROSOFT, I can provide you the following working
				// example of a DROP DOWN LIST that allows you to type more than the
				// FIRST LETTER of what you are looking for in a drop down.
				// I hopw that you find this to be useful. I have been looking for this
				// code for almost a year now. 
				// Again, do not vote for me as this code is from Microsoft.
				// Respectfully, Jason Buck jbuck@esubinc.com
				// Happy Programming.
				// The CODE WAS FOUND at the following location
				// http://msdn.microsoft.com/msdnmag/issues/01/05/web/figures.asp
// Auto-select listbox
// mike pope, Visual Basic UE
// This script and the listbox on this page illustrates one 
// way to create an "auto-complete" listbox, where the
var toFind = ""; // Variable that acts as keyboard buffer
var timeoutID = "";// Process id for timer (used when stopping 
 // the timeout)
timeoutInterval = 250;// Milliseconds. Shorten to cause keyboard 
 // buffer to be cleared faster
var timeoutCtr = 0;// Initialization of timer count down
var timeoutCtrLimit = 3 ; // Number of times to allow timer to count 
 // down
var oControl = "";// Maintains a global reference to the 
 // control that the user is working with.
function listbox_onkeypress(){
// This function is called when the user presses a key while focus is in 
// the listbox. It maintains the keyboard buffer.
// Each time the user presses a key, the timer is restarted. 
// First, stop the previous timer; this function will restart it.
// Which control raised the event? We'll need to know which control to 
// set the selection in.
oControl = window.event.srcElement;
var keycode = window.event.keyCode;
if(keycode >= 32 ){
// What character did the user type?
var c = String.fromCharCode(keycode);
c = c.toUpperCase(); 
// Convert it to uppercase so that comparisons don't fail
toFind += c ; // Add to the keyboard buffer
find();// Search the listbox
timeoutID = window.setInterval("idle()", timeoutInterval); 
// Restart the timer
function listbox_onblur(){
// This function is called when the user leaves the listbox.
function idle(){
// This function is called if the timeout expires. If this is the 
// third (by default) time that the idle function has been called, 
// it stops the timer and clears the keyboard buffer
timeoutCtr += 1
if(timeoutCtr > timeoutCtrLimit){
 timeoutCtr = 0;
function resetToFind(){
toFind = ""
function find(){
// Walk through the select list looking for a match
var allOptions = document.all.item(oControl.id);
for (i=0; i < allOptions.length; i++){
// Gets the next item from the listbox
nextOptionText = allOptions(i).text.toUpperCase();
// By default, the values in the listbox and as entered by the 
// user are strings. This causes a string comparison to be made, 
// which is not correct for numbers (1 < 11 < 2).
// The following lines coerce numbers into an (internal) number 
// format so that the subsequent comparison is done as a 
// number (1 < 2 < 11).
if(!isNaN(nextOptionText) && !isNaN(toFind) ){
 nextOptionText *= 1;// coerce into number
 toFind *= 1;
// Does the next item match exactly what the user typed?
if(toFind == nextOptionText){
// OK, we can stop at this option. Set focus here
oControl.selectedIndex = i;
window.event.returnValue = false;
// If the string does not match exactly, find which two entries 
// it should be between.
if(i < allOptions.length-1){
// If we are not yet at the last listbox item, see if the 
// search string comes between the current entry and the next 
// one. If so, place the selection there.
lookAheadOptionText = allOptions(i+1).text.toUpperCase() ;
if( (toFind > nextOptionText) && 
 (toFind < lookAheadOptionText) ){
 oControl.selectedIndex = i+1;
 window.event.cancelBubble = true;
window.event.returnValue = false;
} // if
} // if
// If we are at the end of the entries and the search string 
// is still higher than the entries, select the last entry
if(toFind > nextOptionText){
oControl.selectedIndex = allOptions.length-1 // stick it 
// at the end
window.event.cancelBubble = true;
window.event.returnValue = false;
} // if
} // else
} // for
} // function
				<select name="FontList" ID="Select1"onkeypress="listbox_onkeypress()" onblur="listbox_onblur()">
			<option id="arial" value="arial">Arial</option>
 <option id="arial black" value="arial black">Arial black</option>
 <option id="arial narrow"value="arial narrow">Arial narrow</option>
 <option id="bookman" value="Bookman">Bookman</option>
 <option id="book antiqua" value="book antiqua">Book Antiqua</option>
 <option id="bookman old style" value="bookman old style">Bookman Old Style</option>
 <option id="century gothic" value="century gothic">Century Gothic</option>
 <option id="comic sans ms" value="comic sans ms">Comic Sans MS</option>
 <option id="courier" value="courier">Courier</option>
 <option id="courier new" value="courier new">Courier New</option>
 <option id="garamond" value="garamond">Garamond</option>
 <option id="georgia" value="georgia">Georgia</option>
 <option id="haettenschweiler" value="haettenschweiler">Haettenschweiler</option>
 <option id="helvetica" value="helvetica">Helvetica</option>
 <option id="impact" value="impact">Impact</option>
 <option id="lucida console" value="Lucida Console">Lucida</option>
 <option id="lucida sans unicode" value="Lucida Sans Unicode">Lucida Sans Unicode</option>
 <option id="marlett" value="Marlett">Marlett</option>
 <option id="microsoft sans serif" value="Microsoft Sans Serif">Microsoft Sans Serif</option>
 <option id="monotype corsiva" value="Monotype Corsiva">Monotype Corsiva</option>
 <option id="ms outlook" value="MS Outlook">MS Outlook</option>
 <option id="newcenturyschlbk" value="NewCenturySchlbk">NewCenturySchlbk</option>
 <option id="palatino" value="Palatino">Palatino</option>
 <option id="palatino linotype" value="Palatino Linotype">Palatino Linotype</option>
 <option id="symbol" value="Symbol">Symbol</option>
 <option id="tahoma" value="Tahoma">Tahoma</option>
 <option id="times" value="Times">Times</option>
 <option id="times new roman" value="Times New Roman">Times New Roman</option>
 <option id="trebuchet ms" value="Trebuchet MS">Trebuchet MS</option>
 <option id="verdana" value="Verdana">Verdana</option>

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