How to call more than one function with return true

Use this for call more than one function with return true :

< script>
function checkform1 ( frm_list1 )
{
return true;
}

function checkform2 ( frm_list2 )
{
return true;
}

function checkform3 ( frm_list3 )
{
return true;
}
< /script>

< form action="" id="frm_itinerary_list" method="post" name="frm_itinerary_list" onsubmit="return (checkform1(this) && checkform2(this) && checkform3(this));">



< /form>