function soloNumeros(field, e){

		var key;
		var keychar;
	

		if (window.event){
			key = window.event.keyCode;
		}
		else if (e){
			key = e.which;
		}
		else{
			event.returnValue = true;
		}

		keychar = String.fromCharCode(key);
	
		if (key>=48 && key<=57){
			event.returnValue = true;
		}
		else {
			event.keyCode=0;
			event.returnValue = false;
		}

	}