An Example showing How to Make Synchronous calls with AJAX Toolkit

1. <apex:page >  
2. <script type="text/javascript">  
3.         var __sfdcSessionId = '{!GETSESSIONID()}';  
4.         </script>  
5.     <script src="../../soap/ajax/29.0/connection.js" type="text/javascript"/>  
6.   
7.     <script>  
8.   
9.     window.onload = setupPage;  
10.         function setupPage() {  
11.             var output = document.getElementById("output");  
12.             var startTime = new Date().getTime()  
13.             try {  
14.                 var queryResult = sforce.connection.query("Select Id, Name, Industry From Account order by Industry limit 30");  
15.                 layoutResults(queryResult, output, startTime);  
16.             } catch(error) {  
17.                 queryFailed(error, output);  
18.             }  
19.         }  
20.         function queryFailed(error, out) {  
21.             out.innerHTML = "<font color=red>An error has occurred:</font> <p>" + error;  
22.         }  
23.         function layoutResults(queryResult, out, startTime) {  
24.             var timeTaken = new Date().getTime() - startTime;  
25.                 if (queryResult.size > 0) {  
26.                 var output = "";  
27.                 var records = queryResult.getArray('records');  
28.                 for (var i = 0; i < records.length; i++) {  
29.                     var account = records[i];  
30.                     output += account.Id + " " + account.Name + " [Industry - "+ account.Industry + "]<BR>";  
31.                 }  
32.                     out.innerHTML = output + "<BR> query completed in: " + timeTaken + " ms.";  
33.                 } else {  
34.                     out.innerHTML = "No records matched.";  
35.                 }  
36.         }  
37.     </script>  
38. <div id="output"></div>  
39. </apex:page>  

Quick Link to parent document:  Embedding API Calls in JavaScript