gracias por su ayuda
Código PHP:
<html><body>
<p><script language="javascript">
var i = 0;
function contador()
{
i = i + 1;
var btn = document.getElementById("boton");
txt_1.value = i ;
}
</script></p>
<form action="" method="post" name="txt_1">
<form action="enviar-escrito.php" method="get" style=border:1px dashed;>
<p>
<label for="txt_1"></label>
</p>
<div align="center">
<table width="365" border="1">
<tr>
<td colspan="2"><div align="center">Conteo de Ingresos
</div> <label for="sl_2"></label></td>
</tr>
<tr>
<td><div align="left">
<select name="sl_1" id="sl_1" onChange="txt_5.value = this.value">
<option>Elija Local</option>
<option>Local_1</option>
<option>Local_2</option>
<option>Local_3</option>
</select>
</div></td>
<td></label>
<label for="txt_5"></label>
<input type="text" name="txt_5" id="txt_5"></td>
</tr>
<tr>
<td><div align="left">
<select name="sl_2" id="sl_2" onChange="txt_6.value = this.value">
<option>Elija Caseta</option>
<option>Caseta_1</option>
<option>Caseta_2</option>
<option>Caseta_3</option>
</select>
</div></td>
<td><label for="txt_6"></label>
<input type="text" name="txt_6" id="txt_6"></td>
</tr>
<tr>
<td><div align="left">hora</div></td>
<td><label for="fecha"></label>
<input name="fecha" type="text" id="fecha" value="<?php echo date("dd/mm/YYYY"); ?>" size="10" /></td>
</tr>
<tr>
<td><div align="left">Conteo Caseta</div></td>
<td><input name="txt_1" type="text" disabled="disabled" id="txt_1" readonly="readonly"></td>
</tr>
<tr>
<td><div align="left">Conteo Local</div></td>
<td><label for="txt_1"></label>
<input name="txt_2" type="text" id="txt_2" readonly="readonly"></td>
</tr>
</table>
</div>
<p>
<input type="button" id="boton" value="Presiona Aqui" onClick="javascript: contador()" />
</p>
<p> </p>
</form>
<p> </p>
</body>
</html>