diff --git a/library/header/examples/color.shdr b/library/header/examples/color.shdr
new file mode 100644
index 0000000..294eeb3
--- /dev/null
+++ b/library/header/examples/color.shdr
@@ -0,0 +1,31 @@
+{$CLASS Color}
+    {$PROPERTY UseColorMap 'false'}
+{$END}
+
+{$CLASS ColorFrag $EXTENDS Color}
+    {$FUNC 'vec4' GetColor $INLINE}
+        {$IF UseColorMap}
+            {$VAR 'vec2' '_texCoord' 'gl_TexCoord[0].st'}
+            {$UNIFORM 'sampler2D' 'uColorMap'}
+            return texture2D(uColorMap, _texCoord);
+        {$ELSE}
+            return gl_Color;
+        {$END}
+    {$END}
+    
+    {$MAIN}
+        gl_FragColor = {$CALL GetColor};
+    {$END}
+{$END}
+
+{$CLASS ColorVert $EXTENDS Color}
+    {$MAIN}
+        gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
+        {$IF UseColorMap}
+            gl_TexCoord[0] = gl_MultiTexCoord0;
+        {$ELSE}
+            gl_FrontColor = gl_Color;
+            gl_BackColor  = gl_Color;
+        {$END}
+    {$END}
+{$END}
\ No newline at end of file
diff --git a/library/header/examples/phonglight.shdr b/library/header/examples/phonglight.shdr
new file mode 100644
index 0000000..3000692
--- /dev/null
+++ b/library/header/examples/phonglight.shdr
@@ -0,0 +1,38 @@
+{$INCLUDE 'color.shdr'}
+
+{$CLASS PhongLight}
+    {$PROPERTY UsePhongLight 'false'}
+    {$IF UsePhongLight}
+        {$VARYING 'vec3' 'vNormal'}
+        {$VARYING 'vec3' 'vVertex'}
+    {$END}
+{$END}
+
+{$CLASS PhongLightFrag $EXTENDS PhongLight ColorFrag}
+    {$MAIN}
+        vec4 color = {$CALL GetColor};
+        {$IF UsePhongLight}
+            vec3 eye       = normalize(-vVertex);
+            vec3 lightVec  = gl_LightSource[0].position.xyz - vVertex;
+            vec3 reflected = normalize(reflect(lightVec, vNormal)); 
+            
+            vec4 ambient  = gl_LightSource[0].ambient * gl_FrontMaterial.ambient;
+            vec4 diffuse  = gl_LightSource[0].diffuse * max(dot(vNormal, lightVec), 0.0) * gl_FrontMaterial.diffuse;
+            vec4 specular = gl_LightSource[0].specular * pow(max(dot(reflected, eye), 0.0), gl_FrontMaterial.shininess) * gl_FrontMaterial.specular;
+            
+            gl_FragColor = vec4((ambient + diffuse) * color) + specular;
+        {$ELSE}
+            gl_FragColor = color;
+        {$END}
+    {$END}
+{$END}
+
+{$CLASS PhongLightVert $EXTENDS PhongLight ColorVert}
+    {$MAIN}
+        {$INHERITED ColorVert $INLINE};
+        {$IF UsePhongLight}
+            vNormal = normalize(gl_NormalMatrix * gl_Normal);
+            vVertex = vec3(gl_ModelViewMatrix * gl_Vertex);
+        {$END}
+    {$END}
+{$END}
\ No newline at end of file
diff --git a/library/header/examples/simple.shdr b/library/header/examples/simple.shdr
new file mode 100644
index 0000000..a00c188
--- /dev/null
+++ b/library/header/examples/simple.shdr
@@ -0,0 +1,9 @@
+{$MAIN}
+    {$PROPERTY EnableTexture 'false'}
+    {$IF EnableTexture}
+        {$UNIFORM 'sampler2D' 'uTexture0'}
+        gl_FragColor = texture2D(uTexture0, gl_TexCoord[0].st);
+    {$ELSE}
+        gl_FragColor = gl_Color;
+    {$END}
+{$END}
\ No newline at end of file
diff --git a/library/header/ulibShaderFile.pas b/library/header/ulibShaderFile.pas
index da983ee..8693f5f 100644
--- a/library/header/ulibShaderFile.pas
+++ b/library/header/ulibShaderFile.pas
@@ -166,7 +166,7 @@ function LibOpen(const aLibName: String; out aError: String): TLibHandle;
 begin
   result := LoadLibraryA(PAnsiChar(AnsiString(aLibName)));
   if (result = 0)
-    then aError := GetLastError()
+    then aError := SysErrorMessage(GetLastError())
     else aError := '';
 end;
 
diff --git a/library/libShaderFile.lpr b/library/libShaderFile.lpr
index 0bd20fa..98c3f52 100644
--- a/library/libShaderFile.lpr
+++ b/library/libShaderFile.lpr
@@ -555,7 +555,7 @@ var
   i: Integer;
 begin
   i := fProperties.IndexOf(aName);
-  if (i <= 0) then begin
+  if (i < 0) then begin
     SetLastError(LSF_ERR_INVALID_PROPERTY_NAME, Format('%s is not a valid/known property name', [aName]));
     result := LastErrorCode;
   end else