Pass function arguments that are variable names into formulae in R functions? -

i looking simple way pass function arguments variable names formulae in r functions.

test dataset:

set.seed(4892) df.pass <- data.frame("alfa"=sample(1:9, 100, replace=t), "beta"=sample(1:9, 100, replace=t),                        "theta"=sample(1:9, 100, replace=t), "out"=runif(100, 0, 1)) 

example analysis (testing if interaction model different) made function:

lrtest(glm(out~alfa*beta, family = binomial("logit"), df.pass),        glm(out~alfa + beta, family = binomial("logit"), df.pass)) 

if goal create generic function invinteract solves problem above arbitrary variable names , data sets, simplest way pass variable names function() arguments formulae terms corresponding positions of out, alfa , beta?

inserting raw variable names formulae not work, because r tries evaluate names objects , finds nothing.

inserting string variable names directly formulae not work either.

is necessary reconstruct formulae paste(), or there more direct way?

glm accepts character string instead of formula. thus, can this:

mytest <- function(df, y, x1, x2) {   lrtest(glm(sprintf("%s ~ %s * %s", y, x1, x2), family = binomial("logit"), df),          glm(sprintf("%s ~ %s + %s", y, x1, x2), family = binomial("logit"), df)) } mytest(df.pass, "out", "alfa", "beta")