Language of error message of simpletypes

Hi,

I've created a few simpletypes to input only digits for example. When i input letters in there, a message shows that i have to change te format the only problem is that the message is in german. Nothing wrong with german 😊 but i would rather have it in english. My browser is english and the language of my user in the SAP portal is set to english . How does Web Dynpro get its locale settings?

Much thanks,

Hugo