1- The valid excuses for missing the Jumu`ah prayer are: being sick or doing essential work that one cannot leave as in the case of one who is treating the sick or dealing with emergency cases in the hospital, or one who works as a security guard for a place of great importance, and other such jobs. 2- If your presence in the hospital at the time of Jumu`ah prayer is necessary for dealing with emergency and accident cases, then there is nothing wrong with your not attending Jumu`ah prayer.

It is permissible to delay Jumu`ah prayer until close to the time for `Asr, in such a way that it will end before the time for `Asr begins. But if there is more than one Jumu`ah in the town, it is better to pray with those who pray Jumu`ah when the time for it begins.

It is permissible to miss Jumu`ah and prayers in congregation in the event of heavy rain, cold wind or snow which is bothersome to people and makes it difficult for them to go to Jumu`ah.

It is permissible to get the attention of one who is speaking during the khutbah by means of a gesture. The Sahabah did that and the Prophet (blessings and peace of Allah be upon him) approved of what they did.

If you catch up with the Imam after he has stood up from Ruku`, this means that you have missed the Jumu`ah prayer. But if a person does not catch up with the prayer for a reason that is beyond his control, then there is no sin on him.