Javascript radio button issue -

im trying validate gender radio buttons. works if not selected, when 1 selected still says "gender not selected"..does know how around this?

i have..

if (!gendermaleradiobutton.checked  || !genderfemaleradiobutton.checked) {     errormessage = errormessage + "gender not selected\n"; }  //displays error messages if (errormessage) {     alert(errormessage); }  //if information valid, submission success. else if(!errormessage) {         alert("submission successful, thank " + firstname.value); }    

you saying "if male button not pressed or female button not pressed, display error message." change first line
if(!gendermaleradiobutton.checked && !genderfemaleradiobutton.checked),
makes "if male button not pressed , female button not pressed, display error message."