function trim(value) {
   var temp = value;
   var obj = /^(\s*)([\W\w]*)(\b\s*$)/;
   if (obj.test(temp)) { temp = temp.replace(obj, '$2'); }
   var obj = / +/g;
   temp = temp.replace(obj, " ");
   if (temp == " ") { temp = ""; }
   return temp;
}

function checkcontactform(passForm) { 
       if (trim(passForm.firstname.value) ==""){
         alert("Please enter your first name")
         passForm.firstname.focus()
         return false
}
       if (trim(passForm.surname.value) ==""){
         alert("Please enter your surname")
         passForm.surname.focus()
         return false
}
       if (trim(passForm.email.value) ==""){
         alert("Please enter your e-mail address")
         passForm.email.focus()
         return false
}
       if (trim(passForm.telephone.value) ==""){
         alert("Please enter your telephone number")
         passForm.telephone.focus()
         return false
}
      return true
}