Dynamically add checkbox param in http request sampler

we are testing for JSF application i have three problem

1) scanerio is to pass checkbox value as request param, based on checkbox check count from previuos page ,

select all(form_extsss:selectAll true true text/plain true) its not working

<input id="form_extsss:selectAll" type="checkbox" name="form_extsss:selectAll" value="true" onclick="selectAll(this)">

indivial selection(how to add dynamically to request param)

<input id="form_extsss:nodeInfoTable:0:checkbox" type="checkbox" name="form_extsss:nodeInfoTable:0:checkbox" value="true" >

for example:

form_extsss:nodeInfoTable:0:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable:1:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable:2:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable:3:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable:4:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable:5:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable:6:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable:7:checkbox    true    true    text/plain  true
form_extsss:nodeInfoTable_selection     true    text/plain  true
form_extsss:nodeInfoTable_scrollState   0,0 true    text/plain  true

only select all param is not working while sending request ,is it possible to add dynamically to param ?

2) Based on option text extract value

xpath extractor: //select[@id="dialogForm:Id"]/option[text()="${prepseries}"]/@value // ${prepseries} passing from csv //not working

Regular Expression Extractor : <option value="([^"]+)".*>${prepproject}</option>

3) since i have alot filter based on cascading drop down creating each http request(its working fine), Is there any way to pass by directly as submit request param

am new to jmeter kindly guide me on this scenarios