Having trouble with my 2nd validation gate in java

The following code is ice cream party calculator. All I am working through right now is the first ageCheck. Right now where it states boolean genderCheck = choice == 1;. The code below runs some calculations and works fine. But then when I added boolean genderCheck = choice == 2; it states the variable has already been declared and wont work. How can I fix my code so that after passing the first ageCheck the second j option pane will take both numbers 1 and 2. Also called choice ==1 and choice ==2;?

    import javax.swing.JOptionPane;
public class l{
public static void main (String[] args) { 
int amount= Integer.parseInt(JOptionPane.showInputDialog( "How many Guest are coming?:"));

    int e;
    double cc;
    double pc;
    double sax= 17.95;
    double tnt;
    double o;
    double d= 1.06;
    double vla=2.03;


 boolean ageCheck = (amount>=1) && (amount<=19);
boolean ageCheck2 = (amount>=20);



 if (ageCheck) {
 int choice= Integer.parseInt(JOptionPane.showInputDialog( " PLEASE ENTER EITHER 1 or 2; 1 is donut ice cream which is 99 cents and 2 is vanilia ice cream that is $1.99?:"));

boolean genderCheck = choice == 1;

            e = 2;

        pc = ((amount/2.0) );
        o =Math.ceil(pc);
        tnt = o *sax;
        cc = (amount*d);


    boolean genderCheck = choice == 2;

            e = 2;

        pc = ((amount/2.0) );
        o =Math.ceil(pc);
        tnt = o *sax;
        cc = (amount*vla);
 if (genderCheck) {

     JOptionPane.showMessageDialog(
        null, "The Cost Peer Room is : " + e + " ICE COST: "+tnt+"MORE COST" +cc+" TOTAL COST" + (e+tnt+cc));}

  else { 

    JOptionPane.showMessageDialog(null,"Error:  Gender must be F or M") ;  
 }}












else if (ageCheck2) {
     String choice =  JOptionPane.showInputDialog( "Enter Flavor: Vanilla =$1 Donut = $2 ");
        boolean genderCheck2 = choice.equalsIgnoreCase("M")  || choice.equalsIgnoreCase("F");


 if (genderCheck2) {

       JOptionPane.showMessageDialog(null,"OUTPUT:  YOUR 2 Years old and either a boy or girl");

 } else { 

    JOptionPane.showMessageDialog(null,"Error: You did not enter male or female as gender") ;  
 }

 } else {

 JOptionPane.showMessageDialog(null,"Error: There must be atleast 1 guest") ;  

 }

}}