function valMaxLength(textarea,length){
	if(textarea.value.length>length){
		alert("El máximo número de caracteres del campo es de: "+length);
		return false;
	}
	return true;
}
function esDigito(sChr){
	var sCod = sChr.charCodeAt(0);
	return ((sCod > 47) && (sCod < 58));
}
function acceptNum(evt){	
	var nav4 = window.Event ? true : false;
	// NOTE: Backspace = 8, Enter = 13, '0' = 48, '9' = 57	
	var key = nav4 ? evt.which : evt.keyCode;	
	return (key <= 13 || (key >= 48 && key <= 57));
}

function valSep(oTxt){
	var bOk = false;
	bOk = bOk || ((oTxt.value.charAt(2) == "-") && (oTxt.value.charAt(5) == "-"));
	bOk = bOk || ((oTxt.value.charAt(2) == "/") && (oTxt.value.charAt(5) == "/"));
	return bOk;
}
function finMes(oTxt){
	var nMes = parseInt(oTxt.value.substr(3, 2), 10);
	var nRes = 0;
	switch (nMes){
		case 1: nRes = 31; break;
		case 2: nRes = 29; break;
		case 3: nRes = 31; break;
		case 4: nRes = 30; break;
		case 5: nRes = 31; break;
		case 6: nRes = 30; break;
		case 7: nRes = 31; break;
		case 8: nRes = 31; break;
		case 9: nRes = 30; break;
		case 10: nRes = 31; break;
		case 11: nRes = 30; break;
		case 12: nRes = 31; break;
	}
	return nRes;
}

function valDia(oTxt){
	var bOk = false;
	var nDia = parseInt(oTxt.value.substr(0, 2), 10);
	bOk = bOk || ((nDia >= 1) && (nDia <= finMes(oTxt)));
	return bOk;
}

function valMes(oTxt){
	var bOk = false;
	var nMes = parseInt(oTxt.value.substr(3, 2), 10);
	bOk = bOk || ((nMes >= 1) && (nMes <= 12));
	return bOk;
}

function valAno(oTxt){
	var bOk = true;
	var nAno = oTxt.value.substr(6);
	bOk = bOk && ((nAno.length == 2) || (nAno.length == 4));
	if (bOk){
		for (var i = 0; i < nAno.length; i++){
			bOk = bOk && esDigito(nAno.charAt(i));
		}
	}
	return bOk;
}
function valFecha(oTxt){
	var bOk = true;
	if (oTxt.value != ""){
		bOk = bOk && (valAno(oTxt));
		bOk = bOk && (valMes(oTxt));
		bOk = bOk && (valDia(oTxt));
		bOk = bOk && (valSep(oTxt));
		if (!bOk){
			alert("Fecha inválida");
			oTxt.value = "";
			oTxt.focus();
		}
	}
}

function set_var_combo(Cselect,val){
	if(val==-1)return false;
	for(i=0; i<Cselect.length; i++){
		if(Cselect.options[i].value==val){
			Cselect.selectedIndex=i;
			return true;
		}
	}
}

function active_field(Cselect,Input){
	if(Cselect.options[Cselect.selectedIndex].value==""){
		Input.readOnly=false;
	}else{
		Input.readOnly=true;
		Input.value="";
	}
}

function set_var_combo_other(Cselect,Input,val){
	if(!set_var_combo(Cselect,val)){
		Input.value=val;
	}else{
		Input.readOnly=true;
	}
}