What's wrong in this pltcl function ?

create function ruldeb(bpchar) returns bpchar as '   set cont $1   set rulaj 0.0   spi_exec -array rec "select valoare
fromvalori where debitor LIKE 
 
\'$cont%\'" {       set rulaj [expr {$rulaj + $rec(valoare)}]   }   if {![info exists GD(conturi_lookup)]} {       set
GD(conturi_lookup)[spi_prepare "select cheie,denumire from 
 
conturi where id=\'\\$1\'" [list bpchar]]   }   spi_execp -count 1 $GD(conturi_lookup) [list $cont]   return "{$cheie}
{$denumire}$rulaj"
 
' LANGUAGE 'pltcl';


is giving the following error:

ERROR:  pltcl: can't read "cheie": no such variable
can't read "cheie": no such variable   while executing
"return "{$cheie} {$denumire} $rulaj""   (procedure "__PLTcl_proc_1759991" line 12)   invoked from within
"__PLTcl_proc_1759991 4:0:1:1:2:"


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Please, could someone give me a clue?

thanks in advance,
Constantin Teodorescu
Braila, ROMANIA