using else if in a function in R

I 'm trying to use else if within a function in R

new<-function(a,b,c,d){
if (a==1){
var1<-100+100+100
var2<-500+500+500
var3<-500-100

}else if (a==2){
var1<-100+100
var2<-500+500
var3<-500-10
} else if (a==3){
var1<-100
var2<-500
var3<-500
}

b<-var1-var2

c<- var2+var3

d<-var3-var1

if (b<100)
{print ("the value is good")
}else if (b>100)
{ print("check teh value")
}else 
{print ("repeat")
}
}

output<-new(3,b,c,d)

I feel something fundamental is wrong with this which I m missing. I 'm trying to use else if to populate the values to be used as an input to call the same fucntion.

Help is greatly appreciated