WoWInterface - Simple texture draw not working

Hello I have this frame created:

Code:

<Ui xmlns="http://www.blizzard.com/wow/ui/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.blizzard.com/wow/ui/

..\FrameXML\UI.xsd">

    <Script file="testtext.lua"/>

    <Frame name="TestText" frameStrata="FULLSCREEN" hidden="true" setAllPoints="true">

        <Scripts>

            <OnLoad>

                self:RegisterEvent("PLAYER_ENTERING_WORLD");

            </OnLoad>

            <OnEvent function="Testtex_OnEvent"/>

        </Scripts>

    </Frame>

</Ui>

and I want to just show a texture in the center of the screen. My testtex.lua file:

Code:

function Testtex_OnEvent(self, event)

        if event == "PLAYER_ENTERING_WORLD" then

                self.texture = self:CreateTexture("texture", "ARTWORK");

                self.texture:SetPoint("CENTER");

                self.texture:SetSize(32,32);

                self.texture:SetTexture("Interface\Icons\INV_Misc_EngGizmos_17");

                self:Show();

        end        

end

Would be really thankful if you could help me out. :)