<aura:component implements="lightning:availableForFlowScreens" access="global">
    <aura:attribute name="greeting" type="String" access="global" default="this is for test!!"/>
    <aura:attribute name="recId" type="String" access="global" />
    
    
    <lightning:recordEditForm aura:id="recordViewForm" 
                              objectApiName="Contact">
        <!-- the messages component is for error messages -->
        <lightning:messages />
        <lightning:inputField value="{!v.recId}" 
                              aura:id="accId" 
                              fieldName="AccountId" 
                              onchange="{! c.onAccountChange}"/>
        
    </lightning:recordEditForm> 
    
</aura:component>