No me funciona este codigo ayuda!!!!!!!!!!!!!!!

[ALONDRA1235]

HOLA A TODOS!!!!!!!

TENGO ESTE CODIGO PERO NO ME FUNCIONA ESPARA PROMEDIAR 3 VALORES

<?php

echo '<script languaje="JavaScript" >

function Sumar(){
interval = setInterval("calcular()",1);
}
function calcular(){
uno = document.autoSumForm.calif1.value;
dos = document.autoSumForm.calif2.value;
tres = document.autoSumForm.calif3.value;


document.autoSumForm.promedio.value = (((uno * 1) + (dos * 1) + (tres * 1))/3);
}
function NoSumar(){
clearInterval(interval);
}
</script>';


echo "<td><input type=text id='calif1' name='calif1' size='5' value='2' onFocus='Sumar();' onBlur='NoSumar();'></td>";
echo "<td><input type=text id='calif2' name='calif2' size='5' value='2' onFocus='Sumar();' onBlur='NoSumar();'></td>";
echo "<td><input type=text id='calif3' name='calif3' size='5' value='' onFocus='Sumar();' onBlur='NoSumar();'></td>";

echo "<td><input type=text name='promedio' MAXLENGTH='3' size='5' ></td>";



?>



GRACIAS.......