class="parameter"><code>program</code></em> is not a value generated by
	OpenGL.</p><p><code class="constant">GL_INVALID_OPERATION</code> is generated if
	<em class="parameter"><code>program</code></em> is not a program object.</p><p><code class="constant">GL_INVALID_VALUE</code> is generated if
	<em class="parameter"><code>index</code></em> is greater than or equal to the
	number of active attribute variables in
	<em class="parameter"><code>program</code></em>.</p><p><code class="constant">GL_INVALID_VALUE