Hi,

I need to implement Sorting in my Visualforce Page on column. I've used my Custom Controller Class to Display records in apex : pageBlockTable, but I'm not able to implement sorting there.Please help. 

Thanks in advance
James

<apex:page standardController="Task" extensions="TaskSearchController">
       <apex:form id="searchForm">
      <apex:PageBlock mode="inlineEdit">      
      <apex:pageblockSection id="searchBlockSection">
       <apex:pageBlockSectionItem id="searchBlockSectionItem">
        <apex:outputLabel >Keyword</apex:outputLabel>
            <apex:panelGroup >
                <apex:inputtext id="searchTextBox" value="{!searchText}">  </apex:inputtext>
                <apex:commandButton Id="btnSearch" action="{!Search}" rerender="renderBlock" status="status" title="Search" value="Search"> </apex:commandButton>
            </apex:panelGroup>
        </apex:pageBlockSectionItem>
    </apex:pageblockSection>
    <apex:actionStatus id="status" startText="Searching... please wait..."/>      
    <apex:pageBlocksection id="renderBlock" >
        <apex:pageblocktable value="{!SearchResults}" var="o" rendered="{!NOT(ISNULL(SearchResults))}">
            <apex:outputLink value="/{!o.Id}">{!o.Subject}</apex:outputLink>
            <apex:column value="{!o.Subject}"/>
            <apex:outputLink value="/{!o.Id}">{!o.Status}</apex:outputLink>
            <apex:column value="{!o.Status}"/>
        </apex:pageblocktable>     
     </apex:pageBlocksection>
      </apex:pageblock>
     </apex:form>
     <apex:enhancedlist type="Activity" height="800" rowsPerPage="50" customizable="False"/>
    </apex:page>


   // Apex 

     public class TaskSearchController
    {
        public apexpages.standardController controller{get;set;}
       
        public Task l;
        public List<Task> searchResults {get; set; }
        public string searchText
    {
    get
        {
            if (searchText==null) searchText = '';
            return searchText;
        }
    set;
        }

    public TaskSearchController(ApexPages.StandardController controller)
    {
        this.controller = controller;
        this.l = (Task) controller.getRecord();
    }
    public PageReference search()
    {
        if(SearchResults == null)
        {
            SearchResults = new List<Task>();
        }
        else
        {
            SearchResults.Clear();
        }

   String qry = 'Select Id,Subject,Status,ActivityDate from Task where Subject like \'%'+searchText+'%\' OR Status like \'%'+searchText+'%\' Order By Subject,Status,ActivityDate';
//    System.debug(qry);
    SearchResults = Database.query(qry);
   // System.debug(SearchResults);
    return null;
  }
}