Load giving a 404 NOT FOUND

[mostwanted]

Why cant i use     details=db.table(request.args(0, cast=int)) function in a load? When i do i get 404 NOT FOUND error, is there  way around this?

function:

def children():
    client=db.client(request.args(0, cast=int))
    db.children.client.default=client.id
    form=SQLFORM(db.children)
    if form.process().accepted:
        response.flash=T('Family Member Registered')
    return locals()

THE VIEW BELOW DOES NOT OPEN THE FORM, IT GIVES ME A 404 ERROR

View

<h1>
    <u>POLICY FORMS (DO REGISTRATION/S FOR {{=client_name(details)}})</u>
</h1>
<br />
<div class="row">
            {{loadmsg = SPAN("loading ...", BR(), SPAN(_class="fa fa-spinner fa-spin"), _style="font-size:20px;")}}
    <div class="col-md-6 form">
            {{=LOAD(url=URL(r=request, f='children.load'),content=loadmsg, ajax=True)}}
    </div>
</div>