File content as of revision 0:0b59e37a2f9b:

#include "mbed.h"

Serial pc(USBTX, USBRX);
DigitalOut led1(LED1);
DigitalOut led2(LED2);
DigitalOut led3(LED3);
DigitalOut led4(LED4);

int main()
{
    pc.printf("Usage: Hit a number 1-5.");
    led1 = false;
    led2 = false;
    led3 = false;
    led4 = false;
    bool flag = true;
    int readin=0;
    while(flag)
    {
        pc.scanf("%i", &readin);
        switch(readin)
        {
            case 1:
                if(!led1) led1 = true;
                else led1 = false;
                break;
            case 2:
                if(!led2) led2 = true;
                else led2 = false;
                break;
            case 3:
                if(!led3) led3 = true;
                else led3 = false;
                break;
            case 4:
                if(!led4) led4 = true;
                else led4 = false;
                break;
            case 5:
                break;
            default:
                break;
        }
        if(readin==5)
        {
            flag = false;
        }
    }
    pc.printf("LED's now locked. ");
}