Well, as someone else noticed, you're comparing some fixed strings that have nothing to do with the $checkvalue, $value1 and $value2 variables. I hadn't even noticed for it's particularly byzantine. Using double quotes would have given you a wrong result. Using single quotes gives you a doubly (or better: multiply!) wrong result!!

You have:

    if(('$checkvalue' gt '$value1') &&
       ('$checkvalue' le '$value2'))
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Make that:

if( $checkvalue > $value1 and
    $checkvalue <= $value2)
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