Fixed bad example for creating a custom shader with an exposed parameter

Fixed bad example for creating a custom material in code and assigning it to a model

en/manual/graphics/effects-and-shaders/custom-shaders.md

@@ -127,8 +127,11 @@ For example, the code below defines and uses the dynamic parameter `Frequency`:
 ```cs
 shader ComputeColorWave: ComputeColor, Texturing
 {
-    stage float Frequency = 1.0f;
-
+	cbuffer PerMaterial
+	{
+		stage float Frequency = 1.0f;
+	}
+	
     override float4 Compute()
     {
         return sin(( Global.Time ) * 2 * 3.14 * Frequency);

en/manual/scripts/create-a-model-from-code.md

@@ -126,8 +126,8 @@ For example:
 	    }
     };
     var material = Material.New(GraphicsDevice, materialDescription);
-    material.Parameters.Set(MaterialKeys.DiffuseValue, Color.Red);
-    model.Materials.Add(material);
+    material.Parameters[0].Set(MaterialKeys.DiffuseValue, Color.Red);
+    model.Materials.Add(0, material);
 ```
 
 ## See also