Due to its asynchronous nature, the $.post(...) response comes later, hence I'm unable to return true/false based on Response value.

2. 
   
3. function updateValue(loadURL, inputValue, recordID, messageDiv) {
4. 
   
5. $(messageDiv).slideUp();
7. var ajax_load = "<img src='images/load.gif' alt='loading...' />";
8. $(messageDiv).html(ajax_load);
9. 
   
10. 
    
11. var truefalse = "";
13. $.post(
14. loadURL,
15. {type: "update", id: recordID, val: inputValue},  
16. function(responseText){
18. if (responseText.indexOf('exists') > -1) {
19. $(messageDiv).html("<div class='error'>'" + inputValue + "' already exists!</div>");
20. $(messageDiv).slideDown();
22. setTimeout(function() {$(messageDiv).slideUp();}, 3000);
23. setTimeout(function() {$('#' + recordID).html(originalVal)}, 2000);
24. truefalse = "false";
25. } else if (responseText.indexOf('invalid') > -1) {
26. $(messageDiv).html("<div class='error'>Invalid Value!</div>");
27. $(messageDiv).slideDown();
28. setTimeout(function() {$(messageDiv).slideUp();}, 3000);
29. } else {
30. setTimeout(function() {$(messageDiv).slideUp();}, 2000);
31. $(messageDiv).html("");
32. }
33. 
    
34. },  
35. "html"  
36. );
37. 
    
39. // HERE: the variable it still empty here. How can I return true/false based on $.post() response.
40. if (truefalse == "false") {
41. return false;
42. }
45. }