<apex:pageblocksection >

        <apex:inputcheckbox value="{!chkBx}" label="Yes">
            <apex:actionSupport event="onchange" rerender="thePanel" action="{!click}"/>
        </apex:inputcheckbox>
       <apex:inputCheckbox label="No"/>
</apex:pageblocksection>
apex:pageblocksection >


<apex:outputPanel id="thePanel">
<apex:pageBlockSectionItem rendered="{!displayInputputText}">
                <apex:outputLabel value="Input Text" />
                <apex:inputText value="{!input}"/>
            </apex:pageBlockSectionItem>
        </apex:outputPanel>
</apex:pageblocksection>

public class CheckboxController{
public String currentEmp{ get; set; }
public Integer expYears{ get; set; }
public Boolean selected{ get; set; }

public CheckboxController(){
    selected = false;
}
}