/* incluir la línea :
	<SCRIPT language=JavaScript1.2 src='control_numeros.js'></script> 
	en el HEAD de la pagina
*/
var nav4 = window.Event ? true : false;

function acceptNum(evt){
	//Nota: Backspace = 8, Enter = 13, '0' = 48, '9' = 57
	//En el control html poner: onKeyPress='return acceptNum(event)'
	var key = nav4 ? evt.which : evt.keyCode;
return (key <= 13 || (key >= 48 && key <= 57));
}

function val_rango(oTxt, nMin, nMax){
    //En el control html poner: onblur='val_rango(this, 1,57)'
	var bOk = true;
	if (oTxt.value != ""){
		if ( oTxt.value < nMin || oTxt.value > nMax ) {
			alert("Valor incorrecto. Debe estar entre " + nMin + " y " + nMax );
			oTxt.value = "";
			oTxt.focus();
			bOk = false;
		}	
	} else {
		bOk = false;
	}
}