function CHKFeedback(f)
{if(f.name.value==""){alert("Please enter your name.");f.name.focus();return false;}
if(f.email.value=="" || f.email.value.search("@") == -1 || f.email.value.search("[.*]") == -1)
{alert("Please enter valid email address.");f.email.focus();return false;}
if(f.tel.value=="")
{alert("Please enter your contact number.\n(i.e. House, office or handphone number.)");f.tel.focus();return false;}
if(f.msg.value=="")
{alert("Please enter your message.");f.msg.focus();return false;}
return true;}