Dynamic Search

==============Vfpage=================
<apex:page controller="DynamicAutoSearch1" sidebar="false" showHeader="false" applyHtmlTag="true" applyBodyTag="true" >

 <apex:form >
<apex:messages />

  <apex:pageBlock title="Search Detials" >
      <apex:pageBlockSection >
      <apex:pageBlockSection columns="2">
  
      <apex:outputLabel >First Name:</apex:outputLabel>
      <apex:inputText value="{!fname}">
             <apex:actionSupport event="onkeyup" action="{!LoadData}" reRender="pbtable"/>
       </apex:inputText>
   
   
     <apex:outputLabel >Last Name:</apex:outputLabel>
          <apex:inputText value="{!lname}">
             <apex:actionSupport event="onkeyup" action="{!LoadData}" reRender="pbtable"/>
           </apex:inputText>
   
     <apex:outputLabel >City:</apex:outputLabel>
          <apex:inputText value="{!city}">
             <apex:actionSupport event="onkeyup" action="{!LoadData}" reRender="pbtable"/>
         </apex:inputText>
        
  
     <apex:outputLabel >State:</apex:outputLabel>
          <apex:inputText value="{!state}">
             <apex:actionSupport event="onkeyup" action="{!LoadData}" reRender="pbtable"/>
          </apex:inputText>
     </apex:pageBlockSection> 
     
        
     <apex:pageBlockSection >     
    
     <apex:pageBlockTable value="{!Candidates}" var="c" id="pbtable" style="bgcolor:yellow">
      
    <apex:column value="{!c.First_Name__c}" />
    <apex:column value="{!c.Last_Name__c}"  />
    <apex:column value="{!c.City__c}"  />
    <apex:column value="{!c.State_Province__c}"  />
    <apex:column value="{!c.Country__c}"  />
         
      </apex:pageblocktable>
   </apex:pageBlockSection>
   </apex:pageBlockSection>
  </apex:pageblock>
 

 </apex:form>
 </apex:page>
=======================================
public with sharing class DynamicAutoSearch1 {
    public DynamicAutoSearch1 (){
        
        can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c];
    }

    public List<Candidate__c> Can{ get; set; }
    public String state { get; set; }
    public String city { get; set; }
    public String lname { get; set; }    
    public String fname { get; set; }    
    public List<Candidate__c> getCandidates (){    
        return can;
    }    
   
    public PageReference LoadData() {
        if(fname != null && lname == '' && city == '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where first_name__c Like:(fname+'%')];
        }
        else if(fname != null && lname != '' && city == '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where Last_Name__c Like:(lname +'%') AND first_name__c Like:(fname+'%') ];
        }

        
        else if(fname != null && lname == '' && city != '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where first_Name__c Like:(fname +'%') AND city__c Like:(city+'%')];
        }
        else if(fname != null && lname == '' && city == '' && state != '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where first_Name__c Like:(fname +'%') AND State_Province__c Like:(state+'%')];
        }
        else if(fname != null && lname != '' && city != '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where first_Name__c Like:(fname +'%') AND Last_Name__c Like:(lname+'%') AND city__c Like:(city+'%')];
        }
        else if(fname != null && lname != '' && city == '' && state != '' ){ 
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where first_Name__c Like:(fname +'%') AND Last_Name__c Like:(lname+'%') AND State_Province__c Like:(state+'%')];
        }
        else if(fname == null && lname != '' && city == '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where Last_name__c Like:(lname+'%')];
        }
        else if(fname == null && lname != '' && city != '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where Last_name__c Like:(lname+'%') AND city__c Like:(city+'%')];
        }
        else if(fname == null && lname != '' && city == '' && state != '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where Last_name__c Like:(lname+'%') AND State_Province__c Like:(state+'%')];
        }
        else if(fname == null && lname != '' && city != '' && state != '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where Last_name__c Like:(lname+'%') AND State_Province__c Like:(state+'%') AND city__c Like:(city+'%')];
        }
        else if(fname == null && lname == '' && city != '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where city__c Like:(city+'%')];
        }
        else if(fname == null && lname == '' && city != '' && state != '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where city__c Like:(city+'%') AND State_Province__c Like:(state+'%')];
        }
        else if(fname == null && lname == '' && city == '' && state != '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where State_Province__c Like:(state+'%')];
        }
        else if(fname != null && lname != '' && city != '' && state != '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where first_Name__c Like:(fname +'%') AND Last_Name__c Like:(lname+'%') AND State_Province__c Like:(state+'%') AND city__c Like:(city+'%')];
        }
        else if(fname == null && lname == '' && city == '' && state == '' ){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c ];
        }
    /*    else if(fname == '' && lname != null){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where Last_Name__c Like:(lname +'%')];
        }
        else if(fname != null && lname != null){
            can =[select id,First_Name__c,Last_Name__c,State_Province__c,City__c,Country__c From Candidate__c where Last_Name__c Like:(lname +'%') AND first_name__c Like:(fname+'%') ];
        }*/
       /* else 
         Apexpages.addmessage(new apexpages.message(apexpages.severity.Error,'Not matching Record'));*/
        return null;
    }   
}