#someDiv 是什么意思？ [关闭]

当用户将鼠标放在该对象上时i想要弹出一条消息：

onmouseover="
    evt.target.setAttribute('opacity', '0.5'); 
    $('#someDiv').show();" 
onmouseout="
    evt.target.setAttribute('opacity','1)');
    $('#someDiv').hide();"

到底是做什么的someDIv意思是？我把文字放在哪里？

我正在这样做，但它根本不显示文本。它只是改变不透明度。

<path 
    d="M 242.96145,653.59282 L 244.83646,650.1553 
       L 247.02397,649.8428 L 247.33647,650.62405 
       L 245.30521,653.59282 L 242.96145,653.59282 
       z M 252.80525,649.99905 L 258.74278,652.49906 
       L 260.77404,652.18656 L 262.33654,648.43654 
       L 261.71154,645.15528 L 257.64902,644.68653 
       L 253.74275,646.40528 L 252.80525,649.99905 
       z M 282.49289,659.6866 L 286.08665,664.99912 
       L 288.43041,664.68662 L 289.52417,664.21787 
       L 290.93042,665.46787 L 294.52419,665.31162 
       L 295.4617,663.90537 L 292.64918,662.18661 
       L 290.77417,658.59284 L 288.74291,655.15533 
       L 283.11789,657.96784 L 282.49289,659.6866 
       z M 302.02423,668.28039 L 303.27423,666.40538 
       L 307.8055,667.34288 L 308.43051,666.87413 
       L 314.36803,667.49913 L 314.05553,668.74914 
       L 311.55552,670.15539 L 307.33675,669.84289 
       L 302.02423,668.28039 z M 307.1805,673.28041 
       L 309.05551,677.03043 L 312.02427,675.93667 
       L 312.33677,674.37416 L 310.77427,672.3429 
       L 307.1805,672.0304 L 307.1805,673.28041 
       z M 313.89928,672.18665 L 316.08679,669.37414 
       L 320.61806,671.7179 L 324.83683,672.81166 
       L 329.0556,675.46792 L 329.0556,677.34293 
       L 325.61809,679.06169 L 320.93056,679.99919 
       L 318.5868,678.59293 L 313.89928,672.18665 
       z M 329.99311,687.18672 L 331.55561,685.93672 
       L 334.83688,687.49923 L 342.18066,690.93674 
       L 345.46193,692.968 L 347.02443,695.31176 
       L 348.89944,699.53053 L 352.80571,702.03054 
       L 352.49321,703.28055 L 348.74319,706.40556 
       L 344.68067,707.81182 L 343.27442,707.18682 
       L 340.30565,708.90557 L 337.96189,712.03059 
       L 335.77438,714.8431 L 334.05562,714.68685 
       L 330.61811,712.18684 L 330.30561,707.81182 
       L 330.93061,705.46806 L 329.3681,699.99928 
       L 327.33684,698.28052 L 327.18059,695.78051 
       L 329.3681,694.84301 L 331.39936,691.87425 
       L 331.86811,690.93674 L 330.30561,689.21798 
       L 329.99311,687.18672 z"
    id="HI"
   style="fill:#ffffd0" 
   onmouseover="evt.target.setAttribute('opacity', '0.5'); $('#id').show();"
   onmouseout="evt.target.setAttribute('opacity','1)'); $('#id').hide();" /> 

'#someDiv' is a CSS3CSS selector which is semantically equivalent to getElementById('someDiv'), in that it will select the element with ID 'someDiv'. So:

document.getElementById('someDiv')

==

// bracket notation will return a DOM element
$("#someDiv")[0]

// leaving it out will return a jQuery object
$("#someDiv")