modalDialog
generates a dialog box prompting the user to
enter a list of text before the process continues. Based on scripts
provided in http://bioinf.wehi.edu.au/~wettenhall/RTclTkExamples/
modalDialog(title,itemlist,entryInit,entryWidth=20,
returnValOnCancel="ID_CANCEL")
Title for the dialog box
Character vector of names that the user must correct
Default string to fill in the entries
Width of entry string
Value for script to return if canceled
Character vector of user entries.