Trim Or Remove space from start and end in textbox, Remove more than one space between two words, trim in javascript on blur.

 function trimdata(el){
         el.value = el.value.replace (/(^\s*)|(\s*$)/gi, "").replace (/[ ]{2,}/gi," ").replace (/\n +/,"\n");
        }

 <asp:TextBox ID="txtSecTitle"  runat="server" TabIndex="15" onblur="trimdata(this);"
                                                    MaxLength="50" CssClass="inputfield" />