iscamtwopropztest(observed1, n1, observed2, n2, hypothesized=0, alternative=NULL, conf.level=NULL 
 This function calculates a two proportion z-test and/or interval. 
  Input the observed numbers of successes or sample proportions (assumed if value less than one),
 Input  the sample sizes, and the hypothesized difference in probability of success/population proportions (default is zero)  
 Optional: Input the form of alternative ("less", "greater", or "two.sided") 
 Optional: Input confidence level(s) for a two-sided confidence interval.
  Optional: Instead of entering the four individual numbers, you can 
 pass in the two-way table of counts.  Be sure to label the datatable in this case.