Jquery/Javascript Automatically select check box and sumit -

i new here , in html , other codes. starting new social website @ wapka have problem. problem want add user group according profile (gender) variable automatically.

example: if user selects female during registration added group named , don't want them see , click button. know how hide don't know how auto select them. here code add user group:

<form method="post" action="setgroup_2.xhtml" >    <input type="checkbox" name="set_group[1]" value="1"  />     his<br/>    <input type="checkbox" name="set_group[1]" value="1" />     her<br/>    <input type="checkbox" name="set_group[1]" value="1"  />    <input type="hidden" name="agroups" value="12=1489bf637bbadc1abce91ee565082bf3"  />    <input type="submit" name="submit" value="set groups" /> </form> 

i hope readers can understand , me.

i think here example of want do. http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_checkbox_value3

and here example of dealing checkbox true,false value. http://www.w3schools.com/jsref/prop_checkbox_checked.asp

i think in case there should radio button not checkbox. that's because there 1 case of gender. (sorry english)