javascript regex to replace space with a hyphen -

i need regex should read string :

1. with 1 unlimited numbers (say upto 10)
2. read space in between
3. with 1 unliimited numbers (say upto 10)

then replace space in string '-'

for ex: 123 456 should replaced 123-456.

there no other characters apart numbers in string.

var str   = 'shop u5, 124 134 millers road'; var regex = /(.*\d{1,10})\s(\d{1,10}.*)/;  if (str.match(regex)) {     str = str.replace(regex, "$1" + "-" + "$2"); }  alert(str) 

output:

'shop u5, 124-134 millers road'