Email syntax on submit buton

Hi everyone,

I am going crazy trying to find the good syntax to add body_message in my send by email Buton.

Here is my line:

formulaire1.#subform[0].#subform[1].Sous-formulaire2.Subform2.Bouton4::preSubmit:form - (JavaScript, client)

this.resolveNode("#event").submit.target = "mailto:xxx [dot] xxx [at] xxx [dot] ca;" + Courriel_Superieur.rawValue +"?subject=Demande de tenue de concours: " + ID.rawValue;

Everythinf works fine but I'd like to add my own body message but I don't know where and how to write it in this line.

If you can help me, thank you. If not,...Merry Christmas