Forum OpenACS Q&A: uploading portrait

hi,
I'm not able to upload a portrait for my dotLRN site .I'm getting the following errors while uploading a portrait

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Here is a detailed dump of what took place at the time of the error, which may assist a programmer in tracking down the problem:

invalid command name "uni_procs::masquerade_name"
while executing
"uni_procs::masquerade_name -name $tmp_filename -masqslash "f""
("lob" arm line 3)
invoked from within
"switch $storage_type {
file {
set filename [cr_create_content_file $item_id $revision_id $tmp_filename]
db..."
("uplevel" body line 62)
invoked from within
"uplevel 1 $transaction_code "
(procedure "db_transaction" line 1)
invoked from within
"db_transaction {

if { [empty_string_p [cr_registered_type_for_mime_type $mime_type]] } {
db_dml mime_type_insert ""
d..."
(procedure "cr_import_content" line 35)
invoked from within
"cr_import_content -image_only -item_id $item_id -storage_type lob -creation_user [ad_conn user_id] -creation_ip [ad_conn peeraddr] [ad_conn pack..."
invoked from within
"set revision_id [cr_import_content -image_only -item_id $item_id -storage_type lob -creation_user [ad_conn user_id] -creation_ip [ad_conn peeradd..."
("uplevel" body line 90)
invoked from within
"uplevel {
ad_page_contract {
adds (or replaces) a user's portrait

@author mailto:philg@mit.edu
@creation-date 26 Sept 1999
@cvs-id $I..."
(procedure "code::tcl::/var/lib/aolserver/servername/packages/acs..." line 2)
invoked from within
"code::tcl::$__adp_stub"
invoked from within
"if { [file exists $__adp_stub.tcl] } {

# ensure that data source preparation procedure exists and is up-to-date
adp_init tcl $__adp_stub
..."
("uplevel" body line 3)
invoked from within
"uplevel {

if { [file exists $__adp_stub.tcl] } {

# ensure that data source preparation procedure exists and is up-to-date
adp_init t..."
(procedure "adp_prepare" line 2)
invoked from within
"adp_prepare "
(procedure "template::adp_parse" line 30)
invoked from within
"template::adp_parse [file root [ad_conn file]] {}"
(procedure "adp_parse_ad_conn_file" line 5)
invoked from within
"$handler"
("uplevel" body line 2)
invoked from within
"uplevel $code"
invoked from within
"ad_try {
$handler
} ad_script_abort val {
# do nothing
}"
invoked from within
"rp_serve_concrete_file [ad_conn file]"
(procedure "rp_serve_abstract_file" line 60)
invoked from within
"rp_serve_abstract_file "$root/$path""
("uplevel" body line 2)
invoked from within
"uplevel $code"
invoked from within
"ad_try {
rp_serve_abstract_file "$root/$path"
set tcl_url2file([ad_conn url]) [ad_conn file]
set tcl_url2path_info..."
I've no idea about the above coding.Also how do i add a gif or JPEG image to my login page?
Please help...........