Simon Cowell says Mel B has given 'America's Got Talent' her ''total focus'' despite going through a messy divorce.

The 58-year-old music mogul - who has worked alongside Mel for several years on 'The X Factor' in the UK and 'America's Got Talent' - has heaped praise on the 43-year-old star for staying strong through her marriage breakdown with Stephen Belafonte and her battle with Post-Traumatic Stress Disorder (PTSD) by not letting her predicament affect her work.

The talent show's boss told The Sun newspaper's Bizarre column: ''When you go through this job for a living and crazy, crazy things happen around you all the time  . . . one thing about Mel is that she comes on this show with total focus.

''She isn't complaining or moaning, she is all about the talent - that is all she talks about. Not herself, and that is hard.

''So I give her a few nods for that.''

Howie Mandel - who joins Mel, Simon and Heidi Klum on the NBC show's panel - also added how he has huge ''love and respect'' for the Spice Girl and says they all have her back.

He said: ''We love and respect each other and we love and respect Mel B.

''We're proud of her and we'll be there for her, whatever she needs.''

Earlier this week, Mel and her ex-husband attended a court hearing in relation to the care of their seven-year-old daughter Madison.

And it was reported that the 'Viva Forever' hitmaker will have to submit to random drug testing as part of her custody agreement for her youngest child.

The former couple were ordered to abstain from alcohol or drugs at least eight hours before spending time with the youngster.

A source explained: ''The court ordered that neither party can consume drugs or alcohol at least eight hours before caring for Madison, and that they must choose a new custody evaluator by September 14 - both sides will submit names and the court will pick which evaluator to go with.

''After the court picks the evaluator then the evaluation will begin.

''The court today did not take custody away from Mel nor did they give Stephen what he wanted. Things could change in terms of custody down the line once the custody evaluation is complete, there has to be a custody evaluation in order for the court to make new custody orders.''

The insider also slammed claims that Mel - who also has daughters Phoenix, 19, and Angel, 11, from previous relationships - didn't call Madison on her birthday at the weekend.

They said: ''Melanie FaceTimed with Madison on her birthday and she also has a birthday party planned for Madison on Thursday this week. The court is not interfering with those birthday plans.''

Mel revealed last month that she planned to check into rehab following an ''incredibly difficult'' six months, but she recently clarified she didn't need help with alcohol or sex addiction.

She said: ''I've been in therapy since my father got diagnosed with cancer nine years ago.

''My therapy changed a little bit because I was in a very intense relationship, which you can all read about in my book.

''I do address a lot of those issues. But you know, no, I'm not an alcoholic. No, I'm not a sex addict.

''You know, I was with the same person for 10 years and that was quite a turmoil, very intense. That's all I can say about it.''