if ( match(block, "^([ \t]*\n)*$")) return;
match(block, "^" mark "[ \t]"); indent = RLENGTH;
sub("^" mark "[ \t]", "", block);
if ( match(block, "^([ \t]*\n)*$")) return;
match(block, "^" mark "[ \t]"); indent = RLENGTH;
sub("^" mark "[ \t]", "", block);