Offsetting a String, Removing SPACEs in a string, CONDENSE??

Hi Experts,

I hv a string and its value is= 'ABCDEF space1 space 2 space3 space4 GHIJKL'.......I mean, there r 4 spaces, I need to hv only 1 space between these..........these number of spaces are varies and the lenghth of string also varies........so, how can I get it? like 'ABCDEF space1 GHIJKL'

thanq