how to increase upload size of a documnet upto 20 MB....in an asp.net application.

HI
masters
In web.cong  file
<httpRuntime executionTimeout=" " maxRequestLength=" " useFullyQualifiedRedirectUrl="false" minFreeThreads="8" minLocalRequestFreeThreads="4" appRequestQueueLimit="100"/>
what to put the value in execution timeout and maxreuesttimeout????
or I have to change some other setting in more places?????
kindly suggest.....it very urgent

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