square move

#include<GL/glut.h>

int a=0;
int start=0;

init()
{
glClearColor(1,0,0,0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(-300,300,-200,200);

}

void disp()
{


glClear(GL_COLOR_BUFFER_BIT);

glColor3f(1,1,1);
//Square


glPushMatrix();

glTranslatef(a,0,0);

glBegin(GL_QUADS);

glVertex2f(0,0);
glVertex2f(50,0);
glVertex2f(50,50);
glVertex2f(0,50);
glEnd();
glPopMatrix();

glFlush();

}


void time(int v)
{

if(start==1)
{

a=a+20;

if (a>360)
{
a=0;
}


glutPostRedisplay();
}

glutTimerFunc(100,time,0);

}

//Mouse Func

void mouse(int button,int state,int x, int y)
{
if(button==GLUT_LEFT_BUTTON&&state==GLUT_DOWN)
{
start=0;
}

  if(button==GLUT_RIGHT_BUTTON&&state==GLUT_DOWN)
   {
start=1;
    }
}

void main(int argc,char** argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_RGB|GLUT_SINGLE);
glutInitWindowSize(600,400);
glutInitWindowPosition(30,10);
glutCreateWindow("Mouse");
init();
glutMouseFunc(mouse);
glutTimerFunc(100,time,0);
glutDisplayFunc(disp);
glutMainLoop();

}