Here you may test different search configuration to understand its behavior.
$params['search_init'] = true; // all fields
$params['search_init'] = false; // no search
$params['search_init'] = 'fftf'; // 3rd field only
$params['search_type'] = 'like'; // default configuration, searches words that looks like the keyword
$params['search_type'] = '='; // searches words that are equal to the keyword
$params['search_type'] = 'beginning_like'; // searches words that the beginning looks like the keyword
$params['search_type'] = 'end_like'; // searches words that the end looks like the keyword
$params['search_html'] = '<span id="#ID#_search_value">Search...</span><a id="#ID#_advanced_search" href="javascript: ctShowAdvancedSearch(\'#ID#\');"><img src="images/advanced_search.png" /></a><div id="#ID#_loader"></div>'; // default configuration
$params['search_html'] = '<a href="javascript: ctShowAdvancedSearch(\'#ID#\');">Show Advanced Search</a>'; // any html
$params['multiple_search_init'] = true; // all fields
$params['multiple_search_init'] = false; // no advanced search
$params['multiple_search_init'] = hide; // all fields but in beginnig they are hidden
$params['multiple_search_init'] = 'fftf'; // 3rd field only
$params['multiple_search_init'] = 'fftf hide'; // 3rd field only but in beginnig they are hidden