how to search a vector/wfs layer

Question

I'm using Geoserver/PostGIS/openLayers

I've succesfully set a vector layer. And now I'm trying to create a search functionality. But something goes wrong.

First I set up the layer and add some basic style for the features. So far, everything is ok.

Then I create a function, using javascript, which comes after the layer. This function gets triggered after the user completes a HTML form and hits the "Search" button.

Here's what's inside the function:

//check for empty fields in the form-if not pass the value in a var 

if (document.getElementById("typeselect").value!=" ") {var filter_a = document.getElementById("typeselect").value;}

if (document.getElementById("eraselect").value!=" ") {var filter_b = document.getElementById("eraselect").value;}

if (document.getElementById("nm").value!="") { var filter_c = document.getElementById("nm").value;}

if (document.getElementById("descr").value!="") { var filter_d = document.getElementById("descr").value;}

if (document.getElementById("chrono").value!="") { var filter_e = document.getElementById("chrono").value;}

//create a style 

var vsd = new OpenLayers.Style();

//put together the final filter, using the vars from above 

//filter_a and filter_b are numbers 

//filter_c to filter_e are texts 

var filter_final = new OpenLayers.Filter.Logical({ type: OpenLayers.Filter.Logical.AND, 

filters: [ new OpenLayers.Filter.Comparison({ 

type: OpenLayers.Filter.Comparison.EQUAL_TO, property: "p_type", value: filter_a }),

 new OpenLayers.Filter.Comparison({ type: OpenLayers.Filter.Comparison.EQUAL_TO, property: "p_era", value: filter_b }), 

new OpenLayers.Filter.Comparison({ type: OpenLayers.Filter.Comparison.LIKE, property: "p_name", value: filter_c }),

 new OpenLayers.Filter.Comparison({ type: OpenLayers.Filter.Comparison.LIKE, property: "p_descr", value: filter_d }), 

new OpenLayers.Filter.Comparison({ type: OpenLayers.Filter.Comparison.LIKE, property: "p_chron", value: filter_e }) ] });



//add the filter as rule to the style 

vsd.addRules([filter_final]);



//apply the style as default 

var vst = new OpenLayers.StyleMap({'default': vsd});



//apply the new style to the layer (named pins) 

pins.styleMap = vst;

This is not working at all. I've tried editing my code, I don't know what to do, I've searched for an answer and nothing really helped me. Please advise...

Thanks.

EDIT

I also added this line at the end and still nothing pins.refresh(); Do I need to use the WFS protocol, combined with the read() ?

EDIT #2 I've replaced pins.refresh(); with pins.refresh({force:true}); and all the features dissappear. I also tried something like this and still nothing. This is a torture...