Hi 
when select picklist value, based on selection , populate table results...but below code not working, can u pls check is there any wrong in below my code

VF page:
<apex:selectList value="{!statusOptions}" multiselect="false" size="1">
     <apex:selectOptions value="{!items}"/>
     <apex:actionSupport event="onselect" action="{!poplateResults}" reRender="messageBlock"/>
     </apex:selectList> 

 <apex:actionStatus id="status" startText="requesting..."/>
<apex:pageBlockSection title="Results" id="results" columns="1">
                    <apex:pageBlockTable value="{!results}" var="c"
                               rendered="{!NOT(ISNULL(results))}">
<apex:column value="{!c.Type}" />
                    <apex:column value="{!c.Subject}" />
                    <apex:column value="{!c.Priority}" />
                    <apex:column value="{!c.Status}" />
                    <apex:column value="{!c.CreatedDate}" />
                     <apex:column value="{!c.Owner.Name}" />    
                    <apex:column value="{!c.SLA_Flag__c}" />
   </apex:pageBlockTable>

Controller class ::
------------------------------
public List<SelectOption> getItems() {

        List<SelectOption> options = new List<SelectOption>();
        
        options.add(new SelectOption('Admin));
        options.add(new SelectOption('Dev'));
        options.add(new SelectOption('Suppp'));
        options.add(new SelectOption('Test));
       
        return options;
    }
 public void poplateResults()
    {
         results = [select CaseNumber,Type, Subject, Priority,Status,CreatedDate,SLA_Flag__c,Owner.Name  from Case where Mail_Box_Name__c=:statusOptions];
    }

please check is there any wrong in my code ...Thanks