This article is for regular plain TextBox control users – normally the spell check (for these textboxes) is initiated by a button click.
Adding the following attribute to a regular TextBox control tag will cause it to be spell checked by the inline checker when the user blurs out, and when the user clicks back in, the textbox changes back to editable mode.
onblur="for(var i=0;i<rsw_scs.length;i++){if(rsw_scs[i].textBoxID==this.id){rsw_scs[i].OnSpellButtonClicked();rsw_scs[i].rsw_tbs.iframe.onmousedown=function(e){if(e.which==1)rsw_getTBSHoldingElement(this).spellChecker.OnSpellButtonClicked()};}}"
This is all one line and assumes that a RapidSpellWInline control has already been setup to spell check the textbox.