why is this not working??

[yoya99]

function replaceTexture() 
local theShader = dxCreateShader( "material/effect.fx" ) 
local theTexture = dxCreateTexture( "material/fireball6.png" ) 
dxSetShaderValue(theShader,"gTexture",theTexture) 
engineApplyShaderToWorldTexture(theShader,"des_dirt1") 
end  
addEventHandler("onClientResourceStart", getResourceRootElement(getThisResource()), replaceTexture) 
function resetTexture() 
if theShader then 
engineRemoveShaderFromWorldTexture ( theShader, "des_dirt1" ) 
end  
end 
addEventHandler("onClientResourceStop", getResourceRootElement(getThisResource()),resetTexture ) 

i made that but it is not working pls help me