ligthning issue

a) I am loading opportunity records by creating a lightning component.

public with sharing class OpportunityController
{   @AuraEnabled
    public static List<Opportunity> getOpportunities()
    {
        List<Opportunity> opporList=[select Name from opportunity where AccountID != NULL];
        return opporList;
    }
}
component Name is : clientside_comp
<aura:component controller="OpportunityController">
   <aura:attribute name="opportunities"
                               type="Opportunity[]"/> 
    <ui:button label="click Me"
               press="{!c.getOppors}"/>  
    <aura:iteration var="opp" 
                    items="{!v.opportunities}">
        <p>{!opp.Name}</p>
    </aura:iteration>
</aura:component>
I controller for component     clientside_comp
({
	"getOppors":function(component) 
    {
	var action=component.get("c.getOpportunities"); 
        //check for response from server 
        action.setCallback(this,function(response)
        {
            var state=response.getState();           
            if (state==="SUCCESS")
            {
                component.set("v.opportunities",response.getReturnValue());  
                                 ============
            }
            else if(state==="INCOMPLETE")
            {
            }
            else if(state==="ERROR")
            {
              var errors=response.getError();
              if (errors)
              {
                alert('From Server:'+errors);  
              } 
            }
        }); //setCallBack method ends here
        $A.enqueueAction(action);
   }
})
<aura:application >
    <c:clientside_comp />
</aura:application>

Its working, but instead of clicking the button I want the to display opportunties list on page load event. How is it possible.