Use a paragraph for every line - if a paragraph is empty, it will be removed automatically.
To create a paragraph, simply use the format - menu.
The easiest way to create an Address Block with a variable number of lines is to use a single variable for the whole address block. Add @address@ where you want it to appear and create a new Text Script where the Selector is @address@.
When you add more lines to a Text Script with other variables selected, Connect will concatenate them together. So with just the variables, you get one long line of text. Of course you don’t want that, so wherever you want a line return, just add a in the “Suffix” box, which is the HTML element for a line return.
The magic comes here: if a field is empty (so let’s say Address2 is empty in your record), that whole line in the Text Script is ignored including the Prefix and Suffix. So you won’t get the Address2 line or the line return after it, ensuring that your block appears as one. Automatic “skip empty line”, basically. 
The same trick can be used to add, for instance, a comma after a name that might not appear (say, because sometimes it’s a company). You put the FirstName field, then the comma and then one or two line returns after that, and if the first name isn’t there, that whole line is removed from your output!
Hi,
If you don’t want to create an address block, click inside a paragraph and click “shit/enter” to go to the next line.
following… If you just click on enter, you create a new paragraph…shit/enter create a new line inside the paragraph… after that, it’s the same thing that a word document.
True, SHIFT+Enter creates a but that won’t remove the line if there is no information in the field. So if you have Address1, Address2, Address3 and there’s only one address line for that record you end up with 2 empty lines in your paragraph. The use of a single Text Script prevents those. I believe that’s what most users will probably want.
I’m agree with you! The best way to do that it’s create an address block… but I just add a complement information. 