void main(void)
{
    gl_TexCoord[0] = gl_MultiTexCoord0;
    gl_TexCoord[1] = gl_MultiTexCoord1;
    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; 
}

uniform sampler2D myTexture1;
uniform sampler2D myTexture2;

void main (void)
{
   vec4 texval1 = texture2D(myTexture, vec2(gl_TexCoord[0]));
   vec4 texval2 = texture2D(myTexture2, vec2(gl_TexCoord[1]));
   
   gl_FragColor = 0.5*(texval1 + texval2);
}