How to check the check box by default in visual force page

Apex Class:

public class checkcontact {

public list<contact> con {get;set;}

public boolean cc{get;set;}

public checkcontact() {

con=new list<contact>();

cc=true;

con=[select name,email from contact];

}

public void change() {

if(cc==false)

cc=true;

else

cc=true;

}

}

VisualForce Page:

<apex:page controller="checkcontact">

<apex:form >

<apex:outputPanel id="p1">

<apex:pageBlock >

<apex:pageBlockTable value="{!con}" var="conlist" >

<apex:column >

<apex:facet name="header"> 

<apex:inputCheckbox value="{!cc}" onclick="change('{!cc}');alert('{!cc}');" />

</apex:facet>

<apex:inputCheckbox selected="true" value="{!cc}" />

</apex:column>

<apex:column >

<apex:facet name="header">Name</apex:facet>

{!conlist.name}

</apex:column>

<apex:column >

<apex:facet name="header">Email</apex:facet>

{!conlist.Email}

</apex:column>

</apex:pageBlockTable>

<apex:actionFunction action="{!change}" name="change" oncomplete="alert('hello');" reRender="p1">

<apex:param name="abc" assignTo="{!cc}" value=""/>

</apex:actionfunction>

</apex:pageBlock>

</apex:outputPanel>

</apex:form>

</apex:page>