part of the data attribute looks like this

data : q : 'pub_title:' + solrCompatableMainQuery,

solrCompatableMainQuery is input from a  text box

the : in pub_title: gets converted to %3A (url encode) as it should.

However  solrCompatableMainQuery needs to be surrounded by double quotes and these are not getting encoded

I have tried this

data : q : 'pub_title:' + '"' +  solrCompatableMainQuery + '"',

and i have tried this (before the ajax call)

solrCompatableMainQuery = '"' + solrCompatableMainQuery + '"'

in both cases the "s etner dont appear in the URL or dont get encoded

interestingly i have tried adding them to the input 
ie searching for "cars" rather than cars

and this does work!

the url produced contains the following

q=pub_title%3A"cats+dogs"

notice how the double quotes are NOT encoded and a + has been added 

What is going wrong here