A warning needed when Fix target date exceeds Resolution SLA

[Carmen Bullock]

I'm requesting the following implementations (both):  

1.  A pop up message that shows the PSL selected a date beyond the SLA resolution date

"Are you sure?  The selected fix target date does not meet the SLA for resolution." 

2.  After updating fix target date, the Time to SLA-Resolution should be red with negative number indicating the delta between the SLA and selected fix target date.  

I am new to the administration side of jira. I have to implement this and I don't have a background in scriptrunner and is new to SLA management. I would appreciate any guidance on how to implement this