By defula displayin all the Records and When u click on alphabets is display Records state with That letter only


===================Visualforce code==================

<apex:page showHeader="false" controller="custom_paginaitonClass">
  <style type="text/css">
      .loadingIcon {
            background-image: url(/img/loading.gif);
            width: 16px;
            height: 16px;
        }
       
  </style>
  <script type="text/javascript">
      function highlight (word) {
         //alert('nnr');       
        document.getElementById (word.id).style.backgroundColor="#E1660D"
        //alert('nnr');   
      }
      function dehighlight (word) {
         //alert('nnr');       
        document.getElementById (word.id).style.backgroundColor="#ffffff"
        //alert('nnr');   
      }
      
</script>
  <apex:form id="form">
    <br/>
    <center>
    <div style="align:right">
       <apex:repeat value="{!Alphabates}" var="A">
           <apex:commandLink value="{!A}" style="text-decoration:none;" onmouseover="highlight(this);" onmouseout="dehighlight(this);" action="{!listRecords}"
            reRender="pb" status="status">
               <apex:param name="alpha" value="{!A}"/>
           </apex:commandLink>
           <apex:outputLabel style="color :Red;">&nbsp;|&nbsp;</apex:outputLabel>
       </apex:repeat>
    </div>
  </center>
  <br/>
  <apex:pageBlock id="pb">
     <apex:actionStatus id="status" >
              <apex:facet name="start"> 
               <apex:outputPanel layout="block" styleClass="message infoM4">
                <apex:image value="/img/loading32.gif" style="height: 15px;">please wait.........</apex:image>
               </apex:outputPanel>
              </apex:facet>
     </apex:actionstatus>
    <apex:pageBlockTable value="{!contactlist}" var="c">
       <apex:column value="{!c.name}"/>
       <apex:column value="{!c.phone}"/>
       <apex:column value="{!c.email}"/>
    </apex:pageBlockTable>
 
  </apex:pageBlock>
  </apex:form>
</apex:page>

==============Controller============================
public class custom_paginaitonClass {
    public string s{set;get;}
    public list<Contact> contactlist { get{
         
    contactlist=Database.Query(contactListQuery);
    system.debug('333333333333333333333333333333333333333333'+contactlist);
      return contactlist ;
    } set; }
    public string contactListQuery{get;set;}
    public PageReference listRecords() {
        standardSetCon = null;    
                if(apexpages.currentpage().getparameters().get('alpha') == 'All')
           s='%';
       else
           s= apexpages.currentpage().getparameters().get('alpha')+'%';
         
       contactListQuery= 'select id,name,phone,Email,Email_1__c,AccountId,Status__c from contact where name like' +'\''+s +'\''+'ORDER BY NAME DESC' + ' limit 5000';
  
        return null;
    }
    
    public ApexPages.StandardSetController standardSetCon{
        get{
            if(standardSetCon==null){
              standardSetCon = new Apexpages.StandardSetController(Database.getQueryLocator(contactListQuery));
               standardSetCon.setPageSize(10);
            }
            return standardSetCon;
        }
        set;
    }
    public List<String> Alphabates { get; set; }
    public  custom_paginaitonClass (){
        Alphabates = new string[]{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','ALL'};
        contactListQuery= 'select id,name,phone,Email,Email_1__c,AccountId,Status__c from contact  ORDER BY NAME ASC limit 1000';   
    }
}