Perl grep

OK here's the situation:
I have got these lines which I have got to parse.
If the line contains a particular string and any element from a previously defined array I need to take that particular line and do some further processing.

if ((grep(/$_[1]/,$1)) && (grep($pattern,@myarr)))
{
    #Do something
}
else
{
   #Do something else
}

And like so many times in my case this obviously is not working.
Any suggestions folks?

It's not entirely clear to me what each of the variables in your example represent, but

grep($pattern,@myarr)

looks through @myarr for occurrences of $pattern which seems at odds with your description of

Apologies for not being able to make myself clear at first.
The file that I am trying to read has got lines like

<start>blahblahblah<tag1>gibberish</tag1><tag2>more of it </tag2>
<tagtosearch>mydata1</tagtosearch>
</start>
<start>blahblahblah<tag1>gibberish</tag1><tag2>more of it </tag2>
<tag3>mydata2</tag3>
</start>

Now my array looks like

@arr=(mydata1,mydata2,mydata3....,mydatan)

The problem is that I cant write

grep(/$myline/,@arr)

Also, does perl grep work like this?

grep(/mydata1|mydata2|mydata3|...|mydatan/,$line)

Thanks a lot.