Changing SVM options parameters

I am trying to set the options for the svmtrain function to increase the number of MaxIter from default. Rather than being the normal name, value pairs it is in a structure called 'options' - what is the necessary syntax for changing such a parameter?

Many thanks

[jnaumann]

In fact, this question doesn't relate specifically to the svmtrain function but rather the syntax for input such parameters in any similar function