if else statements in R

W<- function(w)
{
if (comp[i,1]=1) W[i]<-Wo else

"==" is comparison operator, but "=" is assignment one.
This code also doesn't work:

x <- 0
if (x = 1)

Error: syntax error

But this works:

if (x == 1)

+ 

Chack also help("=="), help("=")

--
WBR,
Timur.