[R] partial least regression

[=?gb2312?Q?=D5=D4=D3=F1=D6=D2?=]

hello r-helpers:
there is a .txt file:
x1	x2	x3	x4	x5	x6	x7	x8	x9	x10	x11	y1
17	5	77	18	19	24	7	24	24	72	52	100
2	6	72	18	17	15	4	12	18	35	42	97.2
17	2	58	10	5	3	4	3	3	40	28	98
17	2	69	14	13	12	4	6	6	50	37	93
2	3	75	20	38	18	6	12	18	73	67	99
14	4	59	16	18	9	4	3	15	47	40	99.95
17	4	87	18	17	12	4	15	12	69	46	100
14	3	74	15	9	12	1	15	12	44	35	98
17	6	76	15	33	21	15	9	18	46	41	100
17	5	76	17	22	18	1	15	9	54	38	100
20	16	98	23	43	27	27	24	27	87	67	99.9
20	6	110	25	36	18	7	18	12	99	88	90
20	6	100	20	19	18	4	15	21	84	60	99.2
17	6	72	13	31	18	5	21	12	52	43	95.6
20	15	104	25	53	30	31	30	30	100	90	99.93
17	13	68	21	42	24	14	18	12	75	69	99.1
17	8	63	14	18	9	10	15	25	39	38	95
20	7	88	19	28	18	7	15	24	61	49	100
20	14	61	18	48	15	11	21	18	48	48	99.91
20	9	94	22	38	21	13	31	12	84	80	99.43
17	7	70	16	28	12	18	12	12	52	38	100
17	6	80	17	46	18	18	24	18	70	69	99.2 

and i write this program:
library(pls)
quality.data<-read.table("d:\\work\\12.txt",col.names=c("x1","x2","x3","x4",
"x5","x6","x7","x8","x9","x10","x11","y1"))
attach(quality.data)
quality.data              #
pairs(cbind(x4,x5,y1))
X<-data.frame(x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,y1)
Y<-data.frame(y1)
quality.simpls<-mvr(X,Y,1:11,method="simpls",validation="CV")  #####error
happens in this row ,and the error information is about: error in
:eval(expr, envir, enclos) :the length of number'envir' is not 1. 

i don't know how to solve this problem.
who can help me make this program correct,please. thank you very much!

                                      kenneth