how to solve error

[alok kumar]

sir,
     I have  got  error  Plz send me solution  of  below error  in
blue:active queue management  algorithm



invalid command name "Queue/Blue"
    while executing
"Queue/Blue create _o246 "
    invoked from within
"catch "$className create $o $args" msg"
    invoked from within
"if [catch "$className create $o $args" msg] {
if [string match "__FAILED_SHADOW_OBJECT_" $msg] {
delete $o
return ""
}
global errorInfo
error "class $..."
    (procedure "new" line 3)
    invoked from within
"new Queue/$qtype"
    ("default" arm line 3)
    invoked from within
"switch -exact $qtype {
ErrorModule {
if { [llength $args] > 0 } {
set q [eval new $qtype $args]
} else {
set q [new $qtype Fid]
}
}
intserv {
set qtyp..."
    (procedure "_o3" line 14)
    (Simulator simplex-link line 14)
    invoked from within
"_o3 simplex-link _o40 _o43 1Mbps 100ms Blue"
    ("eval" body line 1)
    invoked from within
"eval $self simplex-link $n1 $n2 $bw $delay $type $args"
    (procedure "_o3" line 8)
    (Simulator duplex-link line 8)
    invoked from within
"$ns duplex-link $n1 $n2 1Mbps 100ms Blue"
    (file "test-blue.tcl" line 41)






thank  you.