Function about login

In the SCLogin module change the following settings:
* Login View Settings - That will display the login area in a modal popup
* Modal Style - Set to 'Text' so that the Register and Login buttons will be standard text links instead of buttons.

I hope that helps, but if you have any other questions, just let me know.

Thanks,
Alex

1. How can I modify or clear the 'TEXT' in the pics ( MOD_SCLOGIN_LOGINREG_SEPARATOR) ?

That can be found in the /language/xx_YY/xx_YY.mod_sclogin.ini file for your language. Please make sure you remove the ; from the beginning of that line when you edit it.

2. How can I add CSS to change color , size , style ? (I know the CSS,but I don't know how to add it)

We're working on improving this. Currently, there isn't a great CSS file for our SCLogin module to put it in, and we recommend adding any CSS you need to your template. The next release of the SCLogin module (in a few days) will have a theme system with easier CSS files to edit.

3.I can see the popup box before,but now I click the button,and it don't work .

I'm not sure why that's not loading. I'd recommend a few things:
1) Try moving the SCLogin to a different module position. That shouldn't be necessary, but it may change the behavior somehow.
2) Decrease the number of times you're loading jQuery on the page. Currently, the following things are loading jQuery:
a) Your template (I'm guessing) at the top, using the googleapis CDN version
b) K2
c) K2 Store
3) Enable JFBConnect's jquery compatibility layer by enabling the "Include jQuery/Bootstrap" setting in JFBConnect -> Configuration

I hope that helps,
Alex