However, you can always pass as many parameters required to a function using
In that case, your code should look something like following-
OnClientClick='<%# "MyFunctionName(" +Eval("FirstParameter") + ","+Eval("SecondParameter")+" );" %>'
It looks like you want to open a new window as well, which you can write inside the function as well.
Please let me know if something is not clear or if you need further help.