New Post: Dynamic CAMLQuery

Please can you explain me how I can do that?... I can't put dynamic CAMLQuery. I set a variable MyVar = 1; and always search with 1.
CAMLQuery: "<Leq><FieldRef Name='LimiteAsistentes' /><Value Type='Number'>" + MyVar + "</Value></Leq>",

But If I set CAMLQuery: "<Leq><FieldRef Name='LimiteAsistentes' /><Value Type='Number'>21</Value></Leq>", works...

How I can do that?
Thank you for your help!
Capa