I have an html page with multiple forms, I wish to use javascript to check the value of a dropbox (name=os0) and submit if the value is valid.

If I name the form 'myform' I can use this code

<A href="javascript: document.myform.submit();" onclick="if(document.myform.os0.value==56){alert('txt');return false};">Acheter</A>
However, I do not really want to name each form.

Is there a way of checking and submitting the forms without explicity naming them, I thought I could do this using something like

<A href="javascript: document.this.form.submit();" onclick="if(document.this.form.os0.value==56){alert('txt');return false};">Acheter</A>
But I'm having no luck.

Any help appreciated