hello sir, i have used the ramanathan data4-1 file which is about prices of single family home. using Data>sample file>ramanathan>data4-1 which contain as the independent vriables and price as the dependent variable. so i have imported the data and then i selected the model.robust estimation>quantile regression and added price to dependent variable panel and sqft, bedrms, baths as the independent variables. then i have specified 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 as the tau value and then i clicked on ok but i encountered a error saying *invalid quantile specification.* *why it is.pls reply me as early as possible.* *thanks in advance* *with regards* *Kalam narendar reddy* ,