PL/TCL spi_exec insert problem

I've been using the tables and functions below to store large amounts of text
(over the 8k limit) without any problems except for one:  If the the text I'm
trying to store contains any single quote characters ('), then I get a parser
error somewhere in the process.  I'm using php and the process works like this:

INSERT INTO largetext (lgtext) VALUES ('I\'d like to store this');

The lgtext (which could be more than 8k) contains a single quote that is escaped
with \. Php appears to automatically put the \ in. This insert is handled by
the trigger function largetext_trigfun(), which on INSERT does:

spi_exec "SELECT putlgtext(\'largetext_block\', $new_id, \'$NEW($2)\') AS rcode"

The putlgtext() function will break the lgtext ($NEW($2)) up into 7k blocks and
store them in the largetext_block table.

Somewhere in this, the code does not handle the single quote and gives:
PostgreSQL query failed: ERROR: parser error at or near "d"

Please help. :)
The solution is probably simple.  I'm just not so good with TCL.
The largetext_trigfun() could easily be rewritten in PL/SQL if that would help.

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CREATE FUNCTION putlgtext (TEXT, INTEGER, TEXT) RETURNS INTEGER AS '

    set i_table    $1
    set i_id        $2
    set i_t        $3
    set i_seq    0

    while { $i_t != {} } {
        set tblock [string range $i_t 0 7000]
        set i_t [string range $i_t [expr 7000 + 1] end]
        spi_exec "INSERT INTO $i_table (id, text_seq, text_block) VALUES ( $i_id , $i_seq , ''$tblock'' )"
          incr i_seq
    }
    return 0
' LANGUAGE 'pltcl';

CREATE TABLE largetext (
    id    INTEGER PRIMARY KEY,
    lgtext    TEXT -- dummy field
);


CREATE TABLE largetext_block (
    id    INTEGER NOT NULL
        REFERENCES largetext
        ON DELETE CASCADE
        ON UPDATE CASCADE,

    text_seq        INTEGER NOT NULL,

    text_block    TEXT,

    PRIMARY KEY (id, text_seq)
);

CREATE FUNCTION largetext_trigfun() RETURNS OPAQUE AS '
    switch $TG_op {
        INSERT {
            spi_exec "SELECT nextval(\'largetext_seq\') AS new_id"
            set NEW($1) $new_id
            spi_exec "SELECT putlgtext(\'largetext_block\', $new_id, \'$NEW($2)\') AS rcode"
            if { $rcode != 0 } then { return SKIP }
        }
        UPDATE {
            if { $NEW($2) != {} } then {
                spi_exec "DELETE FROM largetext_text WHERE id = $OLD($1)"
                spi_exec "SELECT putlgtext(\'largetext_block\', $OLD($1), \'$NEW($2)\') AS rcode"
                if { $rcode != 0 } then { return SKIP }
            }
        }
    }
    set NEW($2) "ok"
    return [array get NEW]
' LANGUAGE 'pltcl';
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--
Robert B. Easter