ajax code in asp to fetch city.

I need ajax code in asp to fetch city on selecting state.

 

Ajax code is in Javascript and client-side! and ASP/ASP.Net is a server side language. City/States needs database, and ...
It's not as simple as you said in a sentence

 

hah, just done that yesterday with Country > State so I'll give you the example with Country>State and you can figure it out for State>City

I'm using jQuery for Ajax but here's the logic:

ASP page:

I use a database to retrieve values depending on a form request and response.write() everything as a string delimited with "," ...a dirty example without a database would be:

<%
if request.form("country") = "UK" then
response.write("'Avon','Bedfordshire','Berkshire','Buckinghamshire','Cambridgeshire','Cheshire','Cleveland','Clwyd','Cornwall','Cumberland','Cumbria','Derbyshire','Devon','Dorset','Durham','Dyfed','East Sussex','East Suffolk','Essex','Fife','Gloucestershire','Grampian','Greater London','Greater Manchester','Gwent','Gwynedd','Hampshire','Hereford and Worcester','Hertfordshire','Humberside','Huntingdonshire','Isle of Wight','Kent','Lancashire','Leicestershire','Lincolnshire','Lothian','Louth','Merseyside','Mid Glamorgan','Monaghan','Norfolk','North Yorkshire','Northamptonshire','Northern Ireland','Northumberland','Nottinghamshire','Orkney Islands','Oxfordshire','Powys','Shetland','Shropshire','Somerset','South Glamorgan','South Yorkshire','Staffordshire','Strathclyde','Suffolk','Surrey','Sussex','Tayside','Tyne and Wear','Warwickshire','West Glamorgan','West Midlands','West Sussex','West Yorkshire','Western Isles','Wiltshire','Worcestershire','Yorkshire'")

elseif request.form("country") = "USA" then
response.write("'AK', 'AL', 'AR', 'AZ', 'CA', 'CO', 'CT', 'DC', 'DE', 'FL', 'GA', 'HI', 'IA', 'ID', 'IL', 'IN', 'KS', 'KY', 'LA', 'MA', 'MD', 'ME', 'MI', 'MN', 'MO', 'MS', 'MT', 'NC', 'ND', 'NE', 'NH', 'NJ', 'NM', 'NV', 'NY', 'OH', 'OK', 'OR', 'PA', 'RI', 'SC', 'SD', 'TN', 'TX', 'UT', 'VA', 'VT', 'WA', 'WI', 'WV', 'WY'")

end if
%>


HTML page:
There are 3 things you need here:

1. A listener that waits for your drop down list to change
2. A function that does the AJAX call to your ASP page sending the "country" value and then updates the "State" drop down
3. A "Country" drop down list and an empty "State" drop down list

So...in the HEAD of the page add a reference to jQuery and the listener

<script type="text/javascript" src="http://code.jquery.com/jquery-1.6.4.min.js"></script>

<script>
$(document).ready(function() { 
    $('[id=country]').bind('change', function (event) { 
        var pCountry= $(this).val();
        setState(pCountry);
    }); 
});
</script>

Code (markup):

Then add the function that does the AJAX call posting the country variable to your ASp page and updating the drop down:

<script language="JavaScript" type="text/JavaScript">
<!--
function setState(val){


    $.post("getStates.asp", {country: val}, 
   function(data){
         
        var list = data.split(",");
        $("#stateDropdown").empty();
        $("#stateDropdown").append("<option value='All'>All</option>");    
            
        for(var i=0; i<list.length; i++){      
            pName = list[i];
            var dropList = "<option value='" + pName + "'>" + pName + "</option>";    
            $("#stateDropdown").append(dropList);    
        }
        $("#stateDropdown").selectmenu('refresh');
   });
}   


//-->
</script>

Code (markup):

And finally in the BODY have your drop down lists for Country and State

 <select name="country" id="country">
              <option value="All">All</option>
               <option value="United Kingdom">United Kingdom</option>
              <option value="United States">United States</option>
</select>

<select name="stateDropdown" id="stateDropdown">
              <option value="All">All</option>


 </select>

Code (markup):

Hope this helps, shout if you need more explanation