java - How to load a specific DIV when clicked a link without refreshing the whole page? -

i trying days. pleas me this, have no idea how this. if there errors please kind make them correct. thank you.

this html code

<li><a href="#" onclick="getprojectdetails();">   <i class="fa fa-dashboard"></i> <span>new project</span>  <i class="fa fa-angle-left pull-right"></i>  

this ajax code

  <script type="text/javascript">                function getprojectdetails() {              $.show( "project?create", function ( data ) {                  $( "#maincontainer" ).html( data );             });         }        </script> 

this controller class

@controller public class projectcontroller {     private static final logger logger = loggerfactory.getlogger(usercontroller.class);      @requestmapping(value="project", params="create", method= requestmethod.get)//folder name, page name     public string createproject(model model) {         logger.info("create project methof called");         model.addattribute("dto", new projectdto());          return "project/create";     } } 

this data transfer class

    public class projectdto {      @notnull     @size(min=4 , max=30)     private string projectname;      public projectdto() {      }      public string getprojectname() {         return projectname;     }      public void setprojectname(string projectname) {         this.projectname = projectname;          system.out.println("value :  " + projectname);     } } 

here few images of interface. div i'm talking large empty space in images.

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enter image description here

as mentioned in comment, recommend using bootstrap collapisbles need html , css this. below quick example, have through more information: http://www.w3schools.com/bootstrap/bootstrap_collapse.asp

<div class="panel panel-default">     <div class="panel-heading">         <h4 class="panel-title">             <a data-toggle="collapse" href="#collapse">collapsible group</a>         </h4>     </div>     <div id="collapse" class="panel-collapse collapse">         <div class="panel-body">             goes here...         </div>     </div> </div>