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for my custom button:
/00T/e?who_id={!User.Id}&retURL=%2FContact.Id&RecordType=xxxxxxxxxxxxxxx&ent=Task&tsk5=Validate Contact&tsk4={!DATE( YEAR(TODAY()),month( TODAY()),DAY(TODAY()+7))}&tsk2_lkid={!Contact.Id}&tsk2={!Contact.Name}&save=1&retURL={!Contact.Id}


the task should be saved with the prepopulated fields once clicked on the button,  but i've seen in several posts that save=1 stopped working.
Can any body please advise how to put the above into Javascript / onclick JavaScript custom button?

thanks in advance,
agi