apex:selectOptions

1<!-- Page: -->
2<apex:page controller="sampleCon">
3    <apex:form>
4        <apex:selectCheckboxes value="{!countries}" title="Choose a country">
5            <apex:selectOptions value="{!items}"/>
6        </apex:selectCheckboxes><br/>
7        <apex:commandButton value="Test" action="{!test}" rerender="out" status="status"/>
8    </apex:form>
9    <apex:outputPanel id="out">
10        <apex:actionstatus id="status" startText="testing...">
11            <apex:facet name="stop">
12                <apex:outputPanel>
13                    <p>You have selected:</p>
14                    <apex:dataList value="{!countries}" var="c">a:{!c}</apex:dataList>
15                </apex:outputPanel>
16            </apex:facet>
17        </apex:actionstatus>
18    </apex:outputPanel>
19</apex:page>
20  			
21/*** Controller: ***/
22public class sampleCon {
23    String[] countries = new String[]{};
24 
25    public PageReference test() {
26        return null;
27    }
28 
29    public List<SelectOption> getItems() {
30        List<SelectOption> options = new List<SelectOption>();
31        options.add(new SelectOption('US','US'));
32        options.add(new SelectOption('CANADA','Canada'));
33        options.add(new SelectOption('MEXICO','Mexico'));
34
35        return options;
36    }
37 
38    public String[] getCountries() {
39        return countries;
40    }
41 
42    public void setCountries(String[] countries) {
43        this.countries = countries;
44    }
45}