InfoPath Dev

I'm currently trying to link a value to a linked word. The value is calculated in one field 'NumberSource' and I want that value to be equal to a word based on the following formula from Excel with D1 being the value in the Excel document:

=IF(D1<=30,"Improvable",IF(D1<=60,"Close to Successful",IF(D1<85,"Successful", IF(D1<=100,"Outstanding","ERROR")))).

 I've tried replacing D1 with the field as below however the formula errors producing the dreaded 'Expected Value Type' error:

 =IF(NumberSource<=30,"Improvable",IF(NumberSource<=60,"Close to Successful",IF(NumberSource<85,"Successful", IF(NumberSource<=100,"Outstanding","ERROR")))).

 I've noticed that the IF function appears to be not available on InfoPath so was looking for any help on how I can replicate the original formula. Usually I can google my way around these but this time I'm stumped!

InfoPath doesn't have an IF function. Instead, you could use rules with conditions. For example, you could put a rule on the NumberSource field with the condition that NumberSource <= 30, set the field you want to use for your value to "Improvable". Another option would be to have expression boxes on the form with these words and conditional formatting. I'm attaching a sample form that shows these options. Save the form locally, right click and select "Design" to open in design mode, then you can look at what I've done & preview the form. There are rules on field1 that set field 2 for the rule based approach.