// JavaScript Document

 function validaCPF () {
   if (checaCPF(document.professor.cpf.value)) {
       errors="0";
  }
   else {
	 	 errors="1";
     if (errors) alert('CPF Inválido');
		 document.professor.cpf.focus();
		 errors="";
   }
 }

 function checaCPF (CPF) {
	if (CPF.length != 11 || CPF == "00000000000" || CPF == "11111111111" ||
		CPF == "22222222222" ||	CPF == "33333333333" || CPF == "44444444444" ||
		CPF == "55555555555" || CPF == "66666666666" || CPF == "77777777777" ||
		CPF == "88888888888" || CPF == "99999999999")
		return false;
	soma = 0;
	for (i=0; i < 9; i ++)
		soma += parseInt(CPF.charAt(i)) * (10 - i);
	resto = 11 - (soma % 11);
	if (resto == 10 || resto == 11)
		resto = 0;
	if (resto != parseInt(CPF.charAt(9)))
		return false;
	soma = 0;
	for (i = 0; i < 10; i ++)
		soma += parseInt(CPF.charAt(i)) * (11 - i);
	resto = 11 - (soma % 11);
	if (resto == 10 || resto == 11)
		resto = 0;
	if (resto != parseInt(CPF.charAt(10)))
		return false;
        //alert('Correto');
	return true;
 }