help with my if statements

[raptrex]

so my program is checking the month, day and year the user is inputting if it is correct, however, currently, its not working

i believe the problem is the if, else if statements
what im trying to do is if the month (mm is 4,6,9,11, then the day cannot be greater than 31) or if (mm is 1,3,5,7,8,10, then day (dd) cannot be greater than 30)

however, if it enter 4 for month, and 14 for day, and 2009 for year, i get this outputted
Error: Day cannot be greater than 30 if Month is either 4, 6, 9, or 11

which is clearly wrong

import java.util.Scanner;
public class test
{
	public static void main	(String[] args)
	{
	int mm, dd,	yyyy;
	boolean leapyear = false;
	Scanner keyboard = new Scanner(System.in);
		System.out.println("Enter the	Month");
			mm	= keyboard.nextInt();
		System.out.println("Enter the	Day");
			dd	= keyboard.nextInt();
		System.out.println("Enter the	Year");
			yyyy = keyboard.nextInt();
		int checkleap;
		checkleap =	yyyy % 4;
		System.out.println(checkleap);
			if	(checkleap == 0)
				leapyear	= true;
			else if (mm	==	4 || mm == 6 || mm == 9	||	mm	==	11	&&	dd	> 30)
				System.out.println("Error:	Day cannot be greater than	30	if	Month	is	either 4, 6, 9, or 11");
			else if (mm	==	1 || mm == 3 || mm == 5	||	mm	==	7 || mm == 8 || mm == 10 || mm == 12 && dd >	31)
				System.out.println("Error:	Day cannot be greater than	31	if	Month	is	either 1, 3, 5, 7, 8, 10, or 12");
			else if (mm	==	2 && leapyear == true && dd >	29)
				System.out.println("Error:	Day cannot be greater than	29	on	a leap year");
			else if (mm	==	2 && leapyear == false && dd > 28)
				System.out.println("Error:	Day cannot be greater than	28	in	February	on	a nonleap year");;	
	}
}//end program

[shyam]

you need to paranthesize ur or expressions otherwise if even one condition is satisfied the rest of the condition will not be evaluated