not working

please tell me what is wrong with the following algorithm.i am trying to draw a triangle on the screen using the 3 vertices of the array…

GLfloat vertices[]={10,0,20,0,20,10,20,20,10,20,0,20,0,10};
GLubyte coord[]={1,2,3};
void RenderScene(void)
{

  glClear(GL_COLOR_BUFFER_BIT);
  glColor3f(1.0f,0.0f,0.0f);
  glEnableClientState(GL_VERTEX_ARRAY);
  glVertexPointer(2,GL_FLOAT,0,vertices);
  glDrawElements(GL_TRIANGLES,3,GL_UNSIGNED_BYTE,coord); 
  glutSwapBuffers();

}

You must set correctly your projection & model view matrix in order to set the camera properly.
google for glOrtho, glPerspective and glutLookAt

Another error, you are picking the vertex number 1 2 and 3 of your vector.
x y
20, 0
20, 10
20, 20
The three vertex have the same X coordinate, nothing will be drawn.

the problem was , as you said, the fact that the three vertices had the same x coordinate.thank you for your help