openGL ES how to get perspective view?

[kend0g187]

I'm trying to draw a simple cube, rotated 45 deg about y-axis. My drawing code looks like this:

- (void) Draw:
{
	// Set the viewport
	//glFrustumf( -1.0, 1.0, -1.0/(backingWidth/backingHeight), 1.0/(backingWidth/backingHeight), 0.01, 10.0 );
	glViewport ( 0, 0, backingWidth, backingHeight );
	
	// Clear the color buffer
	glClear ( GL_COLOR_BUFFER_BIT );
	
	if( [context API] == kEAGLRenderingAPIOpenGLES2 )
		[self DrawES2];
	else 
		[self DrawES1];
	
	glDrawElements(GL_TRIANGLES, sizeof(indices)/sizeof(GLubyte), GL_UNSIGNED_BYTE, indices);
}
	
- (void) DrawES2
{	
	// Use the program object
	glUseProgram ( programObject );
	
	// Load the vertex data
	glVertexAttribPointer ( 0, 3, GL_FLOAT, GL_FALSE, 0, vVertices );
	glEnableVertexAttribArray ( 0 );
	
	// Load transformation matrix
	GLint mvpLoc = glGetUniformLocation( programObject, "u_mvpMatrix" );
	glUniformMatrix4fv( mvpLoc, 1, GL_FALSE, yRotation );
}

- (void) DrawES1
{	
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	
	glRotatef( 45, 0, 1, 0 );
	
	glVertexPointer(3, GL_FLOAT, 0, vVertices);
	glEnableClientState(GL_VERTEX_ARRAY);
	glColor4f(1.0, 0.0, 0.0, 1.0);
}

What I get is something like this:

What I want is something like this:


When I uncomment the glFrustum line I get no change in ES1 version and app crashes in ES2 version. I'm new to OpenGL so I guess I could be doing something really wrong, but how do I get a perspective view so that the cube looks right?