[R] how to assemble data frame of unknown number of columns in loop

[Nevil Amos]

How do I assemble  ad data fame, consisting of columns form other data 
frames identified in a loop?  cbind is not working as the initial data 
fame has 0 columns and rows.

 > ModList<-dir("./MODEL_DISTS/")
 > ModList<-ModList[grep(pattern="3COLUMNS",ModList)]
 > ALL_MODELS<-data.frame()
 > for (i in ModList){
+ X<-read.table(file=paste("./MODEL_DISTS/",i,sep=""))
+ BASE=sub("3COLUMNS","" , i, fixed = TRUE)
+ names(X)<-c("FromSiteID","ToSiteID","CS_RESISTANCE")
+ ALL_MODELS<-cbind(ALL_MODELS,X[3])
+ }
Error in data.frame(..., check.names = FALSE) :
   arguments imply differing number of rows: 0, 2080


thanks