How can you rotate a quad around its center?

This is what im trying to do but it aint working:

    GL11.glTranslatef(x-getWidth()/2, y-getHeight()/2, 0);      
    GL11.glRotatef(30, 0.0f, 0.0f, 1.0f);
    GL11.glTranslatef(x+getWidth()/2, y+getHeight()/2, 0);  
        DRAW

my main problem is that it renders it off the screen..

draw code:

    GL11.glBegin(GL11.GL_QUADS);
    {
        GL11.glTexCoord2f(0, 0);
        GL11.glVertex2f(0, 0);
        GL11.glTexCoord2f(0, getTexture().getHeight());
        GL11.glVertex2f(0, height);
        GL11.glTexCoord2f(getTexture().getWidth(), getTexture().getHeight());
        GL11.glVertex2f(width,height);
        GL11.glTexCoord2f(getTexture().getWidth(), 0);
        GL11.glVertex2f(width,0);
    }
    GL11.glEnd();