Something

<html>
 	<head>
  		<title>
		Examen
  		</title>
	</head>
<script language=javascript>

 function a()
  {
   if(form1.ra1.checked==true)
    { 
     (form1.ra2.checked=false);
     (form1.text1.value="Matematica");
     (form1.text2.value="Finanzas");
     (form1.text3.value="contabilidad");


    }
  }
 function b()
  {
   if(form1.ra2.checked==true)
    { 
     (form1.ra1.checked=false);
     (form1.text1.value="matematica");
     (form1.text2.value="Programacion");
     (form1.text3.value="Base de datos");
    }
  }
function c()
{
if(form1.check1.checked==true)
{
(form1.text4.value=2);
(form1.text5.value=20000*2);
}
}

</script>

<body>
<form name=form1 method=post action=uno.php>




<p> <center>
<table border=1>
<td>

Administracion <input type=radio name=ra1 onclick=a()>
Informatica <input type=radio name=ra2 onclick=b()>

</center>
</td>
</table>
<p>

<h2><center> Materias </h2></center>
 <center>

        Semestre
       <select>
       <option>{Selecccionar}</option>
       <option>Primero</option>
       <option>Segundo</option>
       <option>Tercero</option>
       </select>

 <table border=2>
  <tr>
   <td><input type=checkbox name=check1 onclick=c()></td><td><input id=text1 name=text1></td>
  <tr>
   <td><input type=checkbox name=check2 onclick=d()></td><td><input id=text2 name=text2></td>
  <tr>
   <td><input type=checkbox name=check2 onclick=e()></td><td><input id=text3 name=text3></td>
  <tr>
  </table>  


<table border=1>
 <tr>
	<td>Total U.C.</td><td><input id=text4 name=text4></td>
 <tr>
	<td>Costo U.C.</td><td><input id=text5 name=text5></td>	
<tr>
  <td> <center><input type=submit value=enviar></center></td>
  <td> <center><input type=reset value=limpiar></center></td>


 </table>
</from>
</body>
</html>