Código PHP:
<?php
if (isset($_GET['clave'])) {
$clave = $_GET['clave'];
//echo $_GET['clave'];
$base = "estudpost";
$sql = "SELECT * FROM alumnos WHERE Cedula LIKE '%$clave%' ";
$conectar = mysql_connect("localhost","root","");
mysql_select_db($base,$conectar);
$result = mysql_query($sql,$conectar);
if ($result && mysql_num_rows($result)>0)
{
$i = mysql_fetch_array($result);
//echo "<br>";
echo $i['Cedula'];
echo " - ";
echo $i['Nombre'];
}
else {
echo "No existe";
}
}
?>
<html>
<body>
<form action ="<? echo($PHP_SELF); ?>" method="get">
<input type="text" name="clave">
<input type="submit" value="Buscar">
</form>
</body>
</html>