THE mum of a missing Valleyfield man is "overwhelmed" by a huge online campaign to help find her son.

Friends of Gavin Fern (30) have used Facebook and Twitter to highlight a police search appeal after he disappeared from his Glasgow flat nearly two weeks ago.

They blitzed celebrity Twitter accounts including Stephen Fry, Lorraine Kelly and Chris Evans asking them to tweet about the former St Columba's High School pupil's disappearance.

It resulted in former PM's wife Sarah Brown urging her 1.1 million Twitter followers to spread the word about his plight.

A Facebook campaign called 'Help Find Gavin' has already attracted almost 1500 followers. The appeal was also highlighted on the STV evening news bulletin on Monday.

Now anxious parent Sandra Fern and Gavin's sister, Helen (32), have paid tribute to his friends for bringing the search campaign to national attention.

Sandra said, "What Gavin's friends have done is absolutely amazing. It shows the emotion is not just felt by us but by them too.

"Me and my daughter wouldn't know where to start � it's overwhelming.

"Strathclyde police have been really good as have police in Dunfermline. Their support is great but all you want is an answer." Sandra, of Scott Street, told the Press Gavin suffered from "vicious" cluster headaches which cause excruciating pain and which hospitalised him for a month earlier this year.

Strathclyde police described his disappearance as "extremely out of character" and said he was "vulnerable".

Sergeant Lynda McGowan said, "Despite an extensive search by officers we have so far been unable to trace Gavin.

"It is extremely out of character for him to go missing and all of his friends and family are becoming increasingly anxious as time goes on, particularly as he has medical issues and is not believed to have taken his medication with him.

"Our enquiries have revealed that Gavin used a bank machine in Central Station in Glasgow city centre on the Saturday afternoon.

"However, we do not know if he then boarded a train. I would therefore appeal to anyone who can shed any light on his current whereabouts, or anyone who may be aware of his movements since Saturday 20th November, to contact us as a matter of urgency.

"We need to know that Gavin is safe and well." The Hewlett Packard consultant was last seen by his flatmate on the Saturday when he left his home in Battlefield at midday.

He had enjoyed a meal with him the evening before and was said to be in good spirits and that the headaches had eased off.

Sandra added, "His flatmate said they had a brilliant meal and some chill-out time.

"On the Saturday, because he hadn't been sleeping, he wrapped up and went out for a walk. Nobody has seen him since. He's never done anything like this before. I'm just hoping he's unwell and has simply gone someplace to help it go away." Gavin is described as 5ft 6in tall, of stocky build, with short brown hair, blue eyes, clean shaven and a fair complexion.

He was last seen wearing a long, grey winter coat and a scarf.

Asked if she had a message for her son, Sandra added, "Just come home son. If you don't want to, let us know you're okay.

"If you've got plans get in touch with someone and just ask someone for help if you are lost." Anyone with information should contact Cathcart police office on 0141 532490. Facebook 'Help Find Gavin'.