var nav4 = window.Event ? true : false;
function valida_numeros(evt){
	//backspace = 8 , enter = 13 , '0' = 48 , '9' = 57
	var key = nav4 ? evt.which : evt.keyCode;
	return (key <= 13 || (key >= 48 && key <= 57));
}

function valida_numeros_menores(evt , valor , limite_menor , limite_mayor){
	//backspace = 8 , enter = 13 , '0' = 48 , '9' = 57
	var key = nav4 ? evt.which : evt.keyCode;
	var numeros_key = new Array();
	for(var i=48;i<=57;i++){
		numeros_key[i] = i - 48;
	}
	nuevo_valor = parseInt(valor + "" +numeros_key[key],10);		
	if(nuevo_valor > limite_mayor || nuevo_valor < limite_menor){
		return (key < 13);	
	}else{
		return (key < 13 || (key >= 48 && key <= 57));
	}	
}
function vacio(q){  
	for( var i=0;i<q.length;i++ ){  
		if(q.charAt(i) != " "){  
			return true ;
		}  
	}  
	return false;
}
function validarEmail(valor){
	if(!valor.match(/^((\w|\.){2,}@)\w{3,}\.\w{2,4}((\.(\w{2}))?)?$/)){
		return false;
	}else{
		return true;
	}
}