Since multiple instances of the script can't be called, can I do this?

function whichSearch($req){

  $searchParameters = array();
  
  switch($req){
    case "blog": // limited to blog documents
      $searchParameters["parent"] = "124" // excludes all documents which haven't id 124 as ancestor (blog id root)
      break;
    case "travels": // subset of the blog - articles regarding travels
      $searchParameters["parent"] = "124" // excludes all documents which haven't id 124 as ancestor (blog id root)
      $searchParameters["filter"] = "tv_content,7,travels"; // excludes all the document which haven't a TV value equal to "travels"
      break;
    case "image gallery": // limited to image galleries
      $searchParameters["parent"] = "300"; // excludes all documents which haven't id 300 as ancestor (image gallery id root)
      break;
    case "china gallery": // limited to image galleries relating to china
      $searchParameters["parent"] = "300"; // excludes all documents which haven't id 300 as ancestor (image gallery id root)
      $searchParameters["filter"] = "tv_content,7,china"; // excludes all the document which haven't a TV value equal to "china"
      break;
    case "comments"
      $searchParameters["parent"] = "124" // excludes all documents which haven't id 124 as ancestor (blog id root)
      $searchParameters["whereSearch"] = "content,jot"; // do the search in the jot elements, not only in documents
      break;
    case "blog2": // limited to blog documents - different presentation
      $searchParameters["parent"] = "124" // excludes all documents which haven't id 124 as ancestor (blog id root)
      $searchParameters["extract"] = "5:introtext,content,tv_content" // uses these elements to set up a maximum of 5 extracts per search results
      break;
    case "products": // search in the custom tables 
      $searchParameters["whereSearch"] = "product,shop" // search in product and shop customs tables (defined in config file)
      $searchParameters["extract"] = "name,shop_name,shop_address"; // uses these elements to set up a maximum of 5 extracts per search results
      break;
  }

  return $searchParameters;
}

<?php
// For a global parameter initialisation use the following syntax $__param = 'value';
// To overwrite parameter snippet call use $param = 'value';

    function travel(){
    
      $config = array();
      
      // travel search definition
      
      $config['documents'] = '104'; 
      $config['whereSearch'] = 'content:alias|jot|maxigallery';
      $config['extract'] = '0';
      $config['breadcrumbs'] = 'Breadcrumbs,showHomeCrumb:0,showCrumbsAtHome:1';
          
      return $config;
    }

    function portraits(){
    
      $config = array();
      
      // portraits search definition
      
      $config['documents'] = '155';
      $config['whereSearch'] = 'content:alias|jot|maxigallery';
      $config['extract'] = '0';
      $config['breadcrumbs'] = 'Breadcrumbs,showHomeCrumb:0,showCrumbsAtHome:1';
    
      return $config;
    }
    
    function travelbooks(){
    
      $config = array();
      
      // travelbook search definition
      
      $config['parents'] = '158';  
      $config['whereSearch'] = 'content:pagetitle,content|tv|jot';
      $config['extract'] = '99:content,jot_content';
      $config['grabMax'] = '3';
      $config['breadcrumbs'] = 'Breadcrumbs,showHomeCrumb:0,showCrumbsAtHome:1';
          
      return $config;
    }

    function unesco(){
    
      $config = array();
      
      // unesco search definition
      
      $config['parents'] = '61';
      $config['whereSearch'] = 'content:pagetitle,content|tv';
      $config['withTvs'] = '+:asTag1';
      $config['breadcrumbs'] = 'Breadcrumbs,showHomeCrumb:0,showCrumbsAtHome:1';
    
      return $config;
    }

?>

[+as.showForm:is=`1`:then=`
<form [+as.formId+] action="[+as.formAction+]" method="post">
    <div id="ajaxSearch_radio">
  		<input type="radio" id="radio_oneword" name="advSearch" value="[+as.oneword+]" [+as.onewordChecked+] /><label for="radio_oneword">[+as.onewordText+]</label>
  		<input type="radio" id="radio_allwords" name="advSearch" value="[+as.allwords+]" [+as.allwordsChecked+] /><label for="radio_allwords">[+as.allwordsText+]</label>
  		<input type="radio" id="radio_exactphrase" name="advSearch" value="[+as.exactphrase+]" [+as.exactphraseChecked+] /><label for="radio_exactphrase">[+as.exactphraseText+]</label>
  		<input type="radio" id="radio_nowords" name="advSearch" value="[+as.nowords+]" [+as.nowordsChecked+] /><label for="radio_nowords">[+as.nowordsText+]</label>
		</div>
		<fieldset>
    <label for="ajaxSearch_input">
      <input id="ajaxSearch_input" class="cleardefault" type="text" name="search" value="[+as.inputValue+]" [+as.inputOptions+] />
    </label>
    <label for="ajaxSearch_submit">
      <input id="ajaxSearch_submit" type="submit" name="sub" value="[+as.submitText+]" />
    </label>
    </fieldset>
    <div id="ajaxSearch_subSearch">
  		<input type="radio" id="subSearch1" name="subSearch" value="travel,1" [+as.subSearch1Checked+] /><label for="subSearch1">Travel pictures gallery</label>
  		<input type="radio" id="subSearch2" name="subSearch" value="portraits,2" [+as.subSearch2Checked+] /><label for="subSearch2">Portrait picture gallery</label>
  		<input type="radio" id="subSearch3" name="subSearch" value="travelbooks,3" [+as.subSearch3Checked+] /><label for="subSearch3">Travel books</label>
  		<input type="radio" id="subSearch4" name="subSearch" value="unesco,4" [+as.subSearch4Checked+] /><label for="subSearch4">The Unesco courrier</label>
 		</div>
</form>
`+]
[+as.showIntro:is=`1`:then=`
<p class="ajaxSearch_intro" id="ajaxSearch_intro">[+as.introMessage+]</p>
`+]
[+as.showResults:is=`1`:then=`
[+as.results+]
`+]

$config['filter'] = 'tv_value,7,travels';

$config['filter'] = 'tv_value,travels,7';